Together with Giustino and Berenice, Arminio is one of three operas Handel wrote within a period of half a year in 1736. He began with the composition of Giustino on 14 August 1736, followed by that of Arminio on 15 September. Having finished Arminio he resumed work on Giustino, which he finished on 20 October. In Mid-December, he went on to compose Berenice.
Arminio was performed for the first time at the Covent Garden Theatre on 12 January 1737, earlier than Giustino. It only saw five performances, the last one on 12 February.
The first modern performance took place on 23 February 1935 in Leipzig in a German-language version by Max Seiffert and Hans Joachim Moser.
The libretto is based on a libretto of the same name by Antonio Salvi, which had been set to music by Alessandro Scarlatti. The storyline deals with the Germanic leader Arminius, who defeated the Romans under Publius Quinctilius Varus in AD 9, and his wife Thusnelda. Although the subject matter thus is historical, the details of the story and the characters, as presented in the opera, are entirely fictional.