<Tr> <Th_colspan="2"> Garrison information </Th> </Tr> <Tr> <Th> Garrison </Th> <Td> 6th Infantry Battalion, Irish Army </Td> </Tr> <P> Custume Barracks (Irish: Dún Chostúim) is a military installation at Athlone in Ireland . </P> <P> The barracks were completed in 1691 . The barracks are named after a Sergeant Custume, who defended the bridge from the forces of King William III during the 1690 Siege of Athlone . The barracks were taken over by forces of the Irish Free State in 1922 and served as the headquarters of 4th Western Brigade until the brigade was disbanded and is now part of 2 Brigade which is headquartered from Cathal Brugha Barracks in Dublin . The barracks remains the home of 6th Infantry Battalion as the lead unit, and 2nd Brigade Artillery Regiment and detachments of 2 Engineer Company and the Medical Corps . </P>

What is the name of athlones army barracks