WColonel Richard Grace (c.1612–1691) was an Irish Royalist soldier who fought for Charles I, Charles II and James II.
WMurrough MacDermod O'Brien, 6th Baron Inchiquin, 1st Baron O'Brien of Burren, 1st Earl of Inchiquin, was known as Murchadh na dTóiteán in reference to extensive burnings of the Irish who would not convert to Anglicanism.
WWilliam Lamport (1611–1659) was an Irish Catholic adventurer, known in Mexico as Don Guillén de Lampart y Guzmán. He was tried by the Mexican Inquisition for sedition and executed in 1659. He claimed to be a bastard son of King Philip III of Spain and therefore the half-brother of King Philip IV.
WBrigadier Juan Mackenna was an Irish-born, Chilean military officer and hero of the Chilean War of Independence. He is considered to have been the creator of the Corps of Military Engineers of the Chilean Army.
WOwen Roe O'Neill, c. 1585 – 6 November 1649, was a Gaelic Irish soldier and one of the most famous of the O'Neill dynasty of Ulster in Ireland. O'Neill left Ireland at a young age and spent most of his life as a mercenary in the Spanish Army serving against the Dutch in Flanders during the Eighty Years' War. Following the Irish Rebellion of 1641, O'Neill returned and took command of the Ulster Army of the Irish Confederates. He is known for his victory at the Battle of Benburb in 1646.
WAlejandro O'Reilly, 1st Count of O'Reilly, KOA, English: Alexander, Count of O'Reilly, Irish: Alastar Ó Raghallaigh, was an Irish-born military reformer and Inspector-General of Infantry for the Spanish Empire in the second half of the 18th century. O'Reilly served as the second Spanish governor of colonial Louisiana, and was the first Spanish official to exercise power in the Louisiana territory after France ceded it to Spain following defeat by Great Britain in the Seven Years' War. For his much-appreciated services to the Crown of Spain, O'Reilly was ennobled as a conde (count), and granted a coat of arms.
WAmbrosio Bernardo O'Higgins, 1st Marquess of Osorno born Ambrose Bernard O'Higgins, was an Irish-Spanish colonial administrator and a member of the O'Higgins family. He served the Spanish Empire as captain general of Chile (1788–1796) and viceroy of Peru (1796–1801). Chilean independence leader Bernardo O'Higgins was his son.
WDonal Cam O'Sullivan Beare, Prince of Beare, 1st Count of Berehaven (1561–1618), was the last independent ruler of the O'Sullivan Beara sept, and thus the last O'Sullivan Beare, a Gaelic princely title, on the Beara Peninsula in the southwest of Ireland during the early seventeenth century, when the English Crown was attempting to secure their rule over the whole island.