[2] The abbey was established by Geoffrey de Marisco, Justicier of Ireland, an Anglo-Norman nobleman who had received large grants of land in Munster from John, King of England.

The abbey, dedicated to the Virgin Mary, was occupied by Canons Regular of the Order of St Augustine until its suppression in 1576 during the Reformation in Ireland.

It was a very wealthy institution, owning large amounts of land across Munster, and the Prior of Killagha was a member of the Irish House of Lords.

However, its proximity to the fortress at Castle Maine during the Desmond Rebellions brought it to the attention of The Crown, which gave orders for the establishment to be closed.

Following the abbey's seizure by the Crown, the buildings and land were leased to Thomas Clinton, one of Queen Elizabeth I's officers in County Kerry.

The Godfrey family built a new stately home in Milltown in 1772, which they named Kilcolman Abbey, but was also known as Bushfield House.