Grellan was a fifth-century Irish saint who lived during the era of Saint Patrick. After reportedly reviving a king's stillborn son through baptism, he was granted land in Connacht to establish a church. He eventually settled near present-day Ballinasloe, where he acted as a mediator during a conflict between the Firbolg and the Gaelic tribe of Colla da Chrioch. Through his spiritual intervention, he is credited with helping the Gaels secure the territory that became known as Uí Maine.