An Irish protestant organization run along masonic lines and dedicated to the preservation of the protestant constitution and the ‘glorious and immortal memory’ of King William III, the victor of the Boyne
(1690). The order was founded in Loughgall (Co. Armagh) in September 1795 by the protestant veterans of a sectarian clash, the battle of the Diamond. It infiltrated the army and yeomanry, and was associated with the bloody suppression of the 1798 rising. Although it experienced a rapid initial growth, both geographically and socially, the order came under parliamentary scrutiny in 1835: the select committee report into its activities was couched in such critical terms that it went into voluntary dissolution. In the later 19th cent. the order enjoyed a revival: it was the vehicle by which the populist demagogue William Johnston mounted an assault on the Party Processions Act in 1867; and it was one of the organizational foundations of popular unionism in the early and mid-1880s. Since 1905 the order has been formally connected with the Ulster Unionist Party
. The order continues to attract a large Ulster protestant membership (perhaps 80,000–100,000). Its most public face is the highly organized summer marches.