Two earlier medieval creations as Baron of Offaly existed for an earlier FitzGerald, who owned land in County Kildare, Ireland,[1][2] including what was then "Offelan", a word that derived from the Irish Uí Faelain and not from what is now County Offaly.
[3] The original grant of the lordship of Offelan was in 1175 to Maurice FitzGerald, one of Strongbow's main supporters.
[4] In 1538–50 the title was recreated for Brian O'Connor Faly, who was based in neighbouring County Offaly.
She was the daughter of Gerald FitzGerald, Lord Offally (1559–1580; the eldest son of the 11th earl, who predeceased his father) and the wife of Sir Robert Digby.
The 20th earl was later created Duke of Leinster in 1766 and the dukedom and barony remain united.