Barry, Garret (Gerat) (d. 1646), army officer, entered Spanish military service about 1601, by his own reckoning. It has been suggested that he departed Kinsale with the Spanish army in March 1601 with his father David Fitz Garrot Barry of Rincorran, his mother and three brothers (ODNB). By Garret Barry's account of 1634 he served four years with the ‘Army of the ocean sea’ followed by twenty-nine years’ service ‘in the warres’ in the low countries and Germany. He rose through the ranks to that of captain in one of Spain's Irish regiments and in December 1632 was awarded a pension as a wounded veteran and appointed to the Flanders council of war. By 1635 he was involved in recruitment of Irishmen for Spanish service. What appears to be a later petition from him recorded his service with the Irish forces at Fuenterrabia in Spain in 1638, and that he was named a ‘Cavalier of the noble order of St. Iago’ (CSPI, 1647–60, 354). He published The siege of Breda (Louvain, 1627), a translation of an account of that event, at which he had served, and an illustrated military handbook, A discourse of military discipline (Brussels, 1634). The latter work addressed the duties and qualities of various ranks of soldiers, up to those of general of infantry and of artillery, with special emphasis on infantry formations, incendiary devices, and fortifications.
In about 1639 he returned to Ireland, apparently at the request of his kinsman David Barry, earl of Barrymore (qv) (to whom he had dedicated his Discourse), and probably to serve in the bishops’ wars (1639–40), for which Barrymore raised troops. In the summer of 1641 he was one of the colonels authorised to transport into foreign service soldiers formerly in the army raised by Lord Deputy Wentworth (qv), and by November 1641 he had assembled 1,000 men at Kinsale. The outbreak of insurrection saw him ordered to disperse these men, though it was reported that he failed to do so, and they may have joined the insurgent forces. By March 1642 he had been chosen as general of the insurgents in Munster, a position subsequently confirmed by the confederate supreme council. His early successes – such as the capture of Limerick castle – were overshadowed by his defeat by Lord Inchiquin (qv), Murrough O'Brien, at Liscarroll in September 1642. In 1643 the Munster leadership appealed to the earl of Castlehaven (qv) to bolster their military position, and he took effective command in the province, though Barry seems to have retained his titular command until his death in March 1646.