The name Dillon can be of Norman or Irish origins. It is the Anglicisation of the Norman de Leon, and also of the Gaelic Ó Duilleáin. The Dillons have always played a prominent part in Irish history. The family once owned so much land in the counties of Longford, Westmeath and Kilkenny that they became known as Dillon’s Country. After the Williamite wars in the seventeenth century a number of the Dillon family served in the continental armies. The name is now widespread across the country, especially in counties Meath, Westmeath and Roscommon.