This distinguished surname belonged to one of Ireland's great princely families who held territory in Breffny (now Cavan and West Leitrim). The prefix 'O' means grandson or male descendant. Rourke is an Anglicization of the Gaelic personal name Ruairc. The clan was noted for its military leaders, several of whom left Ireland to serve abroad, including Prince Joseph O'Rourke who became General-in-Chief of the Russian Empire in 1700 and Count Owen O'Rourke who served Maria Teresa of Austria (1750-1780). Of those who went to France the most noteworthy were Col. Count John O'Rourke (1705-1786) and Father Manus O'Rourke (1660-1741) who during a lifetime as an exile wrote voluminously in the Irish language. In the modern idiom the name is spelt O'Rourke, Rourke, Rorke and Roark. The Coat of Arms granted to the family has the blazon of on a gold field two lions passant in black, the crest being an arm in armour grasping a sword issuing from a gold crown. The first recorded spelling of the family name is shown to be that of Tiernan O'Rourke, Prince of Breffny, which was dated 1172 - Killed in battle, during the reign of Rory O'Connor, High King of Ireland, 1166 - 1198. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.