The Defenders were a Catholic agrarian secret society in 18th-century Ireland, founded in County Armagh.[1] Initially, they were formed as local defensive organisations opposed to the Protestant Peep o' Day Boys; however, by 1790 they had become a secret oath-bound fraternal society made up of lodges.[2] By 1796, the Defenders had allied with the United Irishmen, and participated in the 1798 rebellion.[1] By the 19th century, the organisation had developed into the Ribbonmen.[1]
Into the 21st century, some commentators on ad-hoc nationalist political violence in Ireland will still refer to it generically as Defenderism.[3]