Crossmolina Abbey was founded in 1300 by a member of the deBarry family who held estates in Crossmolina around this time.

Later it passed into the hands of Edmund Albanach Burke of Inniscoe. In 1386 forces from Sligo Castle devastated the orchards of Inniscoe and Castlehill.

In 1526, O’Donnell of Tirconnell captured Crossmolina and Castlehill.

In 1570, Richard Burke of Castlehill opposed the other Burkes of Tirawley in widespread revolt against English misrule.

The English, led by Richard Bingham, won the battle at the windy gap in 1586 and brought the prisoners to an island on Lough Conn.