Garryowen, also known as Garyowen, Garry Owen and Gary Owens, is an Irish tune for a quickstep dance. It was selected as a marching tune for British, Canadian, and American military formations, most notably Gen. George Armstrong Custer's 7th Cavalry.
The word garryowen is derived from Irish, the proper name Eóin (an Irish form of John) and the word for garden garrai – thus "Eóin's Garden". A church dating to the 12th Century by the Knights Templar dedicated to St. John the Baptist is the source of modern area of Garryowen in the city of Limerick, Ireland.
This song emerged during the late 18th century, when it was a drinking song of rich young roisterers in Limerick. It obtained immediate popularity in the British Army through the 5th (or Royal Irish) Regiment of Dragoons.
Beethoven composed two arrangements of the song during 1809–1810 (published 1814–1816 in W.o.O. 152 and W.o.O. 154) with the title, "From Garyone My Happy Home", with lyrics by T. Toms, on romantic themes. The arrangements were part of a large project by George Thomson to engage prominent composers of his time to write arrangements of the folk songs of Ireland, Scotland, and Wales. The composer Mauro Giuliani arranged the tune in Arie Nazionali Irlandesi nr.1-6 Op.125 (Six Irish Airs).
A very early reference to the tune appears in the publication The Life of the Duke of Wellington by , published during 1853. He describes the defence of the town of Tarifa during the Peninsular War, late December 1811. General H. Gough, later Field Marshal Hugh Gough, 1st Viscount Gough, commanding officer of the 87th Regiment (Later the Royal Irish Fusiliers), after repulsing an attack by French Grenadiers "… was not, however, merely satisfied with resistance. When the enemy, scared, ran from the walls, he drew his sword, made the band play 'Garry Owen', and followed the fugitives for two or three hundred yards."