Reilly: This famous clan surname is Irish. The twelth most numerous name in Ireland,  it originates from Raghailligh, the grandson of Conchobhar, king of Connacht in the  10th century, and founder of the clan O'Connor. As such the O'Reillys are kinsman of  the O'Connor's. Traditionally, Irish family names are taken from the heads of tribes  or as in this case from some illustrious warrior. They are usally prefixed by O'  meaning grandson or male descendant of, or Mac denoting "son of". The O'Reilly  territory was around Lough Oughter in Co Cavan and as they increased their strengh,  they extended their territory to Co Westmeath and Longford. The Franciscan Abbey of  Cavan was founded by Giolla Iosa O'Reilly, and over the centuries there have been no  less than thirthy nine O'Reilly abbots, whilst five have been as Archbishops of  Armagh, primates of All Ireland. The celebrated Count Alexander O'Reilly from Co  Meath distinguished himself first in the Austrian services and then in the Spanish  army, and finally as Governor of the French colony of Louisiana where he died in  1797. The O'Reillys have a reputation as astute financiers. In the 15th Century, they  devised their own coinage,and a "Reilly" came to signify a cion of useful value. The  Coat of Armsmost associated with the family is a green shield with two lions rampant  combatant, supporting a dexter hand couped at the wrist erect and apaumee bloody  proper. The first recorded spelling of the family name is shown to be that of Cathal  O'Reilly, Prince of Breffny, which was dated 1237, in the records of Lough Oughter  Monastery, Co Cavan.

The original O'Reilly name was actually "O'Raghailligh" and is  pronounced "O'Rahilly".  It was then changed to "O'Reilly"; then to Reilly then  finally to "Riley".  It's one of the original 12 surnames of Ireland.  The original  tribe orginated from Breffny (now called County of Cavan)in Northern Ireland.   The reputation of the tribe was tenancious, extremely tough, often violent,  and 
 warlike, valiant behavior.  There was a strong rivalry between O'Rourke's  (Lords of Beffny) and the O'Reilly's (head of clan chief).  In 1878,  O'Reilly's 
 were landlords of 30,000 acres in Ireland and were the most powerful clan in  Breffny.  The family of O'Sheridan's were devoted followers of the  O'Reilly's.  "The life of a Riley" expression was started in 1854 and it was  formed due to their lax, rich, "party" attitude.

O'Reilly is our true surname. Some where in the early 1900 hundreds our last  name was spelled Reilly then changed to Riley.

Family Mottoe: 
 "Fortitudine et Prudentia" with means in english "With Fortitude and Prudence"