Beethoven was the grandson of Ludwig van Beethoven (1712–1773), a musician from the town of Mechelen in the Austrian Duchy of Brabant (in what is now the Flemish region of Belgium) who had moved to Bonn at the age of 21. Ludwig was employed as a bass singer at the court of Clemens August, Archbishop-Elector of Cologne, eventually rising to become, in 1761, Kapellmeister (music director) and hence a pre-eminent musician in Bonn. The portrait he commissioned of himself towards the end of his life remained displayed in his grandson's rooms as a talisman of his musical heritage. Ludwig had one son, Johann (1740–1792), who worked as a tenor in the same musical establishment and gave keyboard and violin lessons to supplement his income. Johann married Maria Magdalena Keverich in 1767; she was the daughter of Heinrich Keverich (1701–1751), who had been the head chef at the court of the Archbishopric of Trier. Beethoven was born of this marriage in Bonn. There is no authentic record of the date of his birth; however, the registry of his baptism, in the Catholic Parish of St. Remigius on 17 December 1770, survives, and the custom in the region at the time was to carry out baptism within 24 hours of birth. There is a consensus, (with which Beethoven himself agreed) that his birth date was 16 December, but no documentary proof of this.

Beethoven's first music teacher was his father. He later had other local teachers: the court organist Gilles van den Eeden (d. 1782), Tobias Friedrich Pfeiffer (a family friend, who provided keyboard tuition), and Franz Rovantini (a relative, who instructed him in playing the violin and viola). From the outset his tuition regime, which began in his fifth year, was harsh and intensive, often reducing him to tears; with the involvement of the insomniac Pfeiffer, there were irregular late-night sessions with the young Beethoven being dragged from his bed to the keyboard. His musical talent was obvious at a young age. Johann, aware of Leopold Mozart's successes in this area (with his son Wolfgang and daughter Nannerl), attempted to promote his son as a child prodigy, claiming that Beethoven was seven on the posters for his first public performance in March 1778.

In 1780 or 1781, Beethoven began his studies with his most important teacher in Bonn, Christian Gottlob Neefe.

Beethoven soon began working with Neefe as assistant organist, at first unpaid (1782), and then as a paid employee (1784) of the court chapel.

His first three piano sonatas, WoO 47, sometimes known as "Kurfürst" ("Elector") for their dedication to the Elector Maximilian Friedrich (1708–1784), were published in 1783.

In the year 1783, the first printed reference to Beethoven appeared in the Magazin der Musik - "Louis van Beethoven a boy of 11 years and most promising talent. He plays the piano very skilfully and with power, reads at sight very well the chief piece he plays is Das wohltempierte Klavier of Sebastian Bach, which Herr Neefe puts into his hands.

Neefe taught Beethoven composition; in March 1783 appeared Beethoven's first published work, a set of keyboard variations (WoO 63).

In the period 1785–90 there is virtually no record of Beethoven's activity as a composer. This may be attributed to the lukewarm response his initial publications had attracted, and also to ongoing problems in the Beethoven family. His mother died in 1787, shortly after Beethoven’s first visit to Vienna, where he stayed for about two weeks and almost certainly met with Mozart.

In 1789 Beethoven's father was forcibly retired from the service of the Court (as a consequence of his alcoholism) and it was ordered that half of his father's pension be paid directly to him for support of the family. He contributed further to the family's income by teaching (to which Wegeler said he had "an extraordinary aversion") and by playing viola in the court orchestra. This familiarized him with a variety of operas, including works by Mozart, Gluck, and Paisiello. Here he also befriended Anton Reicha, a composer, flutist, and violinist of about his own age who was a nephew of the court orchestra's conductor, Josef Reicha.

He was introduced in these years to several people who became important in his life. He often visited the cultivated von Breuning family, where he taught piano to some of the children, and where the widowed Frau von Breuning offered him a motherly friendship. Here he also met Franz Wegeler, a young medical student, who became a lifelong friend (and was to marry one of the von Breuning daughters). The von Breuning family environment offered an alternative to his home life, which was increasingly dominated by his father's decline. Another frequenter of the von Breuning's was Count Ferdinand von Waldstein, who became a friend and financial supporter during Beethoven's Bonn period. Waldstein was to commission in 1791 Beethoven's first work for the stage, the ballet Musik zu einem Ritterballett (WoO 1).

Beethoven left Bonn for Vienna in November 1792, amid rumors of war spilling out of France; he learned shortly after his arrival that his father had died. Over the next few years, Beethoven responded to the widespread feeling that he was a successor to the recently deceased Mozart by studying that master's work and writing works with a distinctly Mozartean flavour.

Maximilian Friedrich's successor as the Elector of Bonn was Maximilian Franz. He gave some support to Beethoven, appointing him Court Organist and paying towards his visit to Vienna of 1792.

With Haydn's departure for England in 1794, Beethoven was expected by the Elector to return home to Bonn. He chose instead to remain in Vienna, continuing his instruction in counterpoint with Johann Albrechtsberger and other teachers. In any case, by this time it must have seemed clear to his employer that Bonn would fall to the French, as it did in October 1794, effectively leaving Beethoven without a stipend or the necessity to return. However, a number of Viennese noblemen had already recognised his ability and offered him financial support, among them Prince Joseph Franz Lobkowitz, Prince Karl Lichnowsky, and Baron Gottfried van Swieten.

His first public performance in Vienna was in March 1795, where he first performed one of his piano concertos. Shortly after this performance, he arranged for the publication of the first of his compositions to which he assigned an opus number, the three piano trios, Opus 1. These works were dedicated to his patron Prince Lichnowsky, and were a financial success; Beethoven's profits were nearly sufficient to cover his living expenses for a year.

Beethoven told the English pianist Charles Neate (in 1815) that he dated his hearing loss from a fit he suffered in 1798 induced by a quarrel with a singer. During its gradual decline, his hearing was further impeded by a severe form of tinnitus. As early as 1801, he wrote to Wegeler and another friend Karl Amenda, describing his symptoms and the difficulties they caused in both professional and social settings (although it is likely some of his close friends were already aware of the problems). The cause was probably otosclerosis, perhaps accompanied by degeneration of the auditory nerve.

In 1799 Beethoven participated in (and won) a notorious piano 'duel' at the home of Baron Raimund Wetzlar (a former patron of Mozart) against the virtuoso Joseph Wölfl, and in the following year, he similarly triumphed against Daniel Steibelt at the salon of Count Moritz von Fries.

In May 1799, he taught piano to the daughters of Hungarian Countess Anna Brunsvik. During this time, he fell in love with the younger daughter Josephine.

Beethoven's eighth piano sonata the "Pathétique" (Op. 13), published in 1799 is described by the musicologist Barry Cooper as "surpassing any of his previous compositions, in the strength of character, depth of emotion, level of originality, and ingenuity of motivic and tonal manipulation."

He did not immediately set out to establish himself as a composer, but rather devoted himself to study and performance. Working under Haydn's direction, he sought to master counterpoint. He also studied violin under Ignaz Schuppanzigh. Early in this period, he also began receiving occasional instruction from Antonio Salieri, primarily in Italian vocal composition style; this relationship persisted until at least 1802, and possibly as late as 1809.

In the spring of 1801, he completed The Creatures of Prometheus, a ballet. The work received numerous performances in 1801 and 1802, and he rushed to publish a piano arrangement to capitalize on its early popularity.

In the spring of 1802, he completed the Second Symphony, intended for performance at a concert that was canceled. The symphony received its premiere instead at a subscription concert in April 1803 at the Theater an der Wien, where he had been appointed composer in residence. In addition to the Second Symphony, the concert also featured the First Symphony, the Third Piano Concerto, and the oratorio Christ on the Mount of Olives. Reviews were mixed, but the concert was a financial success; he was able to charge three times the cost of a typical concert ticket.

On the advice of his doctor, he moved to the small Austrian town of Heiligenstadt, just outside Vienna, from April to October 1802 in an attempt to come to terms with his condition. There he wrote the document now known as the “Heiligenstadt Testament”, a letter to his brothers which records his thoughts of suicide due to his growing deafness and records his resolution to continue living for and through his art. The letter was never actually sent and was discovered in the composer’s papers after his death. The letters to Wegeler and Amenda were not so despairing; in them, Beethoven commented also on his ongoing professional and financial success at this period, and his determination, as he expressed it to Wegeler, to “seize Fate by the throat; it shall certainly not crush me completely.” In 1806, Beethoven noted on his musical sketches "Let your deafness no longer be a secret – even in art."

During the early 1800s his income came from publishing his works, from performances of them, and from his patrons, for whom he gave private performances and copies of works they commissioned for an exclusive period prior to their publication. Some of his early patrons, including Prince Lobkowitz and Prince Lichnowsky, gave him annual stipends in addition to commissioning works and purchasing published works. Perhaps his most important aristocratic patron was Archduke Rudolf of Austria, Archbishop of Olomouc and Cardinal-Priest, and the youngest son of Emperor Leopold II, who is 1803 or 1804 began to study piano and composition with him. They became friends, and their meetings continued until 1824. Beethoven was to dedicate 14 compositions to Rudolph, including the Archduke Trio Op. 97 (1811) and Missa Solemnis Op. 123 (1823).

Beethoven’s return to Vienna from Heiligenstadt was marked by a change in musical style and is now often designated as the start of his middle or "heroic" period characterized by many original works composed on a grand scale. According to Carl Czerny, Beethoven said, "I am not satisfied with the work I have done so far. From now on I intend to take a new way." An early major work employing this new style was the Third Symphony in E flat Op. 55, known as the Eroica, written in 1803-4. The idea of creating a symphony based on the career of Napoleon may have been suggested to Beethoven by Count Bernadotte in 1798.

Beethoven, sympathetic to the ideal of the heroic revolutionary leader, originally gave the symphony the title "Bonaparte", but disillusioned by Napoleon declaring himself Emperor in 1804, he scratched Napoleon's name from the manuscript's title page, and the symphony was published in 1806 with its present title and the subtitle "to celebrate the memory of a great man." The Eroica was longer and larger in scope than any previous symphony. When it premiered in early 1805 it received a mixed reception. Some listeners objected to its length or misunderstood its structure, while others viewed it as a masterpiece.

Beethoven continued to attract recognition. In 1807 the musician and publisher Muzio Clementi secured the rights for publishing his works in England, and Haydn's former patron Prince Esterházy commissioned a mass (the Mass in C, Op. 86) for his wife's name-day. But he could not count on such recognition alone. A colossal benefit concert which he organized in December 1808, and was widely advertised, including the premieres of the Fifth and Sixth (Pastoral) symphonies, the Fourth Piano Concerto, extracts from the Mass in C, the scena and aria Ah! perfido Op. 65 and the Choral Fantasy op. 80. There was a large audience, (including Czerny and the young Ignaz Moscheles). But it was under-rehearsed, involved many stops and starts, and during the Fantasia Beethoven was noted shouting at the musicians "badly played, wrong, again!" The financial outcome is unknown.

The imminence of war reaching Vienna itself was felt in early 1809. In April Beethoven had completed writing his Piano Concerto No. 5 in E flat major, Op. 73, which the musicologist Alfred Einstein has described as “the apotheosis of the military concept” in Beethoven’s music. Archduke Rudolf left the capital with the Imperial family in early May, prompting Beethoven’s piano sonata ‘’Les Adieux’’, (Sonata No. 26, Op. 81a), actually entitled by Beethoven in German “Das Lebewohl”(“ The Farewell”), of which the final movement, ’’Das Wiedersehen” (‘’The Return’’), is dated in the manuscript with the date of Rudolf’s homecoming of 30 January 1810.

At the end of 1809, Beethoven was commissioned to write incidental music for Goethe's play Egmont.

Malfatti was the niece of Beethoven's doctor, and he had proposed to her in 1810. He was 40, she was 19. The proposal was rejected. She is now remembered as the recipient of the piano bagatelle Für Elise.

While he was at Teplitz in 1812 he wrote a ten-page love letter to his "Immortal Beloved", which he never sent to its addressee.[84] The identity of the intended recipient was long a subject of debate, although the musicologist Maynard Solomon has effectively proved that the intended recipient must have been Antonie Brentano; other candidates have included Juliette Guicciardi, Therese Malfatti and Josephine Brunsvik.

In early 1813 Beethoven apparently went through a difficult emotional period, and his compositional output dropped. His personal appearance degraded—it had generally been neat—as did his manners in public, notably when dining.

Beethoven was finally motivated to begin significant composition again in June 1813, when news arrived of Napoleon's defeat at the Battle of Vitoria by a coalition led by the Duke of Wellington. The inventor Mälzel persuaded him to write a work commemorating the event for his mechanical instrument the Panharmonicon.

Beethoven's hearing loss did not prevent him from composing music, but it made playing at concerts—an important source of income at this phase of his life—increasingly difficult. (It also contributed substantially to his social withdrawal.) Czerny remarked that Beethoven could still hear speech and music normally until 1812. But in April and May 1814, playing in his Piano Trio, Op. 97 (known as the ’’Archduke’’), he made his last public appearances as a soloist. The composer Louis Spohr noted: “the piano was badly out of tune, which Beethoven minded little since he did not hear it there was scarcely anything left of the virtuosity of the artist I was deeply saddened.” From 1814 onwards Beethoven used for conversation ear-trumpets designed by Johann Nepomuk Maelzel, and a number of these are on display at the Beethoven-Haus in Bonn.

Between 1815 and 1819 Beethoven's output dropped again to a level unique in his mature life. He attributed part of this to a lengthy illness (he called it an "inflammatory fever") that he had for more than a year, starting in October 1816.

In 1819 Beethoven began work on the Diabelli Variations and the Missa Solemnis, composing over the next few years piano sonatas and bagatelles to satisfy the demands of publishers and the need for income. He was ill again for an extended time in 1821 and completed the Missa in 1823, three years after its original due date. Around 1822 his brother Johann began to assist him in his business affairs, including him lending him money against ownership of some of his compositions.

Two commissions in 1822 improved Beethoven's financial prospects. The Philharmonic Society of London offered a commission for a symphony, and Prince Nikolas Golitsin of Saint Petersburg offered to pay Beethoven's price for three string quartets. The first of these commissions spurred him to finish the Ninth Symphony, which was first performed, along with the Missa Solemnis, on 7 May 1824, to great acclaim at the Kärntnertortheater.

He wrote the last quartets amidst failing health. In April 1825 he was bedridden and remained ill for about a month. The illness—or more precisely, his recovery from it—is remembered for having given rise to the deeply felt slow movement of the Fifteenth Quartet, which he called "Holy song of thanks ('Heiliger Dankgesang') to the divinity, from one, made well." He went on to complete the quartets now numbered Thirteenth, Fourteenth, and Sixteenth. The last work completed by Beethoven was the substitute final movement of the Thirteenth Quartet, which replaced the difficult Große Fuge. Shortly thereafter, in December 1826, illness struck again, with episodes of vomiting and diarrhea that nearly ended his life.

In 1825, his nine symphonies were performed in a cycle for the first time, by the Leipzig Gewandhaus Orchestra under Johann Philipp Christian Schulz. This was repeated in 1826.

Beethoven was bedridden for most of his remaining months, and many friends came to visit. He died on 26 March 1827 at the age of 56 during a thunderstorm. His friend Anselm Hüttenbrenner, who was present at the time, said that there was a peal of thunder at the moment of death. An autopsy revealed significant liver damage, which may have been due to heavy alcohol consumption. It also revealed considerable dilation of the auditory and other related nerves.

Beethoven's funeral procession on 29 March 1827 was attended by an estimated 20,000 people. Franz Schubert, who died the following year and was buried next to him, was one of the torchbearers. He was buried in a dedicated grave in the Währing cemetery, north-west of Vienna, after a requiem mass at the church of the Holy Trinity (Dreifaltigkeitskirche). His remains were exhumed for study in 1862 and moved in 1888 to Vienna's Zentralfriedhof. In 2012, his crypt was checked to see if his teeth had been stolen during a series of grave robberies of other famous Viennese composers.

Beethoven then turned to write the string quartets for Golitsin. Of these "Late Quartets", Beethoven's favorite was the Fourteenth Quartet, op. 131 in C♯ minor, which he rated as his most perfect single work. The last musical wish of Schubert was to hear the Op. 131 quartet, which he did on 14 November 1828, five days before his death.

statue to Mozart had been unveiled in Salzburg, Austria, in 1842.

There is a museum, the Beethoven House, the place of his birth, in central Bonn. The same city has hosted a musical festival, the Beethovenfest, since 1845. The festival was initially irregular but has been organized annually since 2007.

The Beethoven Monument in Bonn was unveiled in August 1845, in honor of the 75th anniversary of his birth. It was the first statue of a composer created in Germany, and the music festival that accompanied the unveiling was the impetus for the very hasty construction of the original Beethovenhalle in Bonn (it was designed and built within less than a month, on the urging of Franz Liszt).

Vienna did not honor Beethoven with a statue until 1880.