King Laoghaire, whom St. Patrick met at Tara, had three brothers living in the north-west of Ireland, one of whom was Conal. Conal was a guest at Tara, when on Easter morning Patrick preached and converted many. Conal extracted a promise from the Saint to visit Tyrconnel (Conal's country, i.e. Donegal), a promise which St. Patrick kept several years later. He came through Barnesmore Gap, down the valley of the Finn, where he founded the church of Donoughmore (Donough is derived from Dominica - the Lord's Day; and wherever the name Donough or Donoughmore is met, it signifies a church founded by Patrick on a Sunday).

It was in the parish of Clonleigh near Ballindrait that St. Patrick met Conal and his two sons, Fergus and Conal (jnr.). St. Patrick ran forward to bless and salute Fergus, something which annoyed the younger Conal. Patrick explained that a great Saint would be born of Fergus' line - and he had, in prophetic anticipation, saluted him first (in the years to come Fergus became the grandfather of St. Columba). To placate Conal however, Patrick took Conal's shield and marked it with a cross, as a token that he and his should defend the faith - hence the shield of Tyrconnel.