Galloway during the 12th–13th century was a Norse-Gaelic dominant society. Upon the death in 1234 of Lord Alan of Galloway, who had held the position of Constable of Scotland, Alexander II determined that Alan’s inheritance would be divided between his three legitimate daughters and their husbands. Alan’s illegitimate son Tomás, believed that he should inherit, under the rules of tanistry. Alexander II rejected Tomás‘a claim, dividing Galloway amongst Alan's daughters, Ela married to Roger de Quincy, Dervorguilla married to John I de Balliol and Christiana married to William de Forz.
Revolt
The Galloway lords and landholders supported Tomás‘s claim over that of Alexander II’s feudalism partitioning of Galloway and joined a revolt against Alexander II. Tomás, along with his associate Gille Ruadh wished to maintain Galloway's status as an independent sub-kingdom. Alexander II raised an army and invaded Galloway in July 1235. The magnates accompanying Alexander II, were: Walter Fitz Alan, High Steward of Scotland, Justiciar of Scotia, Walter Olifard, Justiciar of Lothian, Walter Comyn, jure uxoris Earl of Mentieth, Máel Coluim, Earl of Angus and Caithness, Walter Bisset, Lord of Aboyne and Alan Durward. The Scottish army was ambushed near Kenmore and was in danger of being routed, however the appearance of Fearchar, Earl of Ross with his forces, at the rear of the Galloway army, forced the Gallwegian army to flee. Gille Ruadh and Tomás escaped to Ireland. After leaving Walter Comyn in charge to subdue the province, Alexander II returned into Scotland and proceeded to Berwick, for his sister Marjorie's impending wedding to Gilbert Marshal, Earl of Pembroke, which occurred on 1 August. Comyn went about ravaging the rebels lands in Galloway, as well as sacking the monastic establishments at Glenluce Abbey and Tongland Abbey, for supporting the rebellion. Tomás and Gille Ruadh returned from Ireland with a new army, forcing Comyn to flee Galloway. This forced Patrick II, Earl of Dunbar to lead a Scottish army, with Adam, Abbot of Melrose, and Gilbert, Bishop of Galloway into Galloway. Patrick II, with the Abbot and Bishop, former friends of Alan of Galloway, were able to force the submission of Tomás and Gille.
Aftermath
The revolt's failure ensured that the Lordship of Galloway was no longer a united and distinct sub-kingdom of northern Britain and fell under the control of the Kingdom of Scotland. Tomás was sent to confinement in Edinburgh Castle, before being released and spending his days in captivity at Barnard Castle in England, as a hostage of his sister Dervorguilla.