Bedridden

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.