The tower itself is of 14th-century construction. The importance of this friary is signified by the fact that it was here that O'Neill and the other Ulster chiefs acknowledged their submission to Richard II, King of England, at the end of 14th-century.
The Hospital of St. Mary d'Urso was founded in 1206-14 by Ursus de Swemele and his wife Christina, it lay at the western end of the town. It was subsequently taken over by the Augustinians. In 1330 the flood of the Boyne did considerable damage to the monastery.The building was restored mainly thanks to the generosity of the Brandon family.
The religious life of Drogheda was utterly transformed by the measures taken to progress the Reformation in Ireland. The great abbeys, priories and hospitals all disappeared and their lands taken by the Crown.