Napoleon's forces fought two Coalition armies, commanded by the British Duke of Wellington and the Prussian Prince Blücher, at the Battle of Waterloo on 18 June 1815. Wellington's army withstood repeated attacks by the French and drove them from the field while the Prussians arrived in force and broke through Napoleon's right flank.

At the June 1856 Republican National Convention, though Lincoln received support to run as vice president, John C. Frémont and William Dayton comprised the ticket, which Lincoln supported throughout Illinois. The Democrats nominated former Secretary of State James Buchanan and the Know-Nothings nominated former Whig President Millard Fillmore.

On 18 June, the jurors retired to deliberate on the verdict, returning after ten hours. They found Garvey himself guilty, but his three co-defendants not guilty. Garvey was furious with the verdict, shouting abuse in the courtroom and calling both the judge and district attorney "damned dirty Jews". Imprisoned in The Tombs jail while awaiting sentencing, he continued to blame a Jewish cabal for the verdict; in contrast, prior to this he had never expressed anti-semitic sentiment and was supportive of Zionism.

The Anglo-German Naval Agreement (AGNA) of 18 June allowed German tonnage to increase to 35 per cent of that of the British navy. Hitler called the signing of the AGNA "the happiest day of his life", believing that the agreement marked the beginning of the Anglo-German alliance he had predicted in Mein Kampf.

The United Kingdom made an Anglo-German Naval Agreement regulating the size of Kreigsmarine in relation to the United Kingdom's Royal Navy.