thumb|left|The remains of the late 13th-century parish church In the 13th century, despite Edgar's quitclaim, Scottish forces attempted to conquer parts of Suðreyjar, culminating in the indecisive Battle of Largs. In 1266, the matter was settled by the Treaty of Perth, which transferred the whole of Suðreyjar to Scotland, in exchange for a very large sum of money. The Treaty expressly preserved the status of the rulers of Suðreyjar; the MacRory lands, excepting Bute, Arran, and Jura, became the Lordship of Garmoran, a quasi-independent crown dependency, rather than an intrinsic part of Scotland. Following this, the Norse longhouses were gradually abandoned, in favour of new Blackhouses and a new parish church was built at Howmore for South Uist.
thumb|left|The remains of the late 13th-century parish church In the 13th century despite Edgar's quitclaim Scottish forces attempted to conquer parts of Suðreyjar culminating in the indecisive Battle of Largs In 1266 the matter was settled by the Treaty of Perth which transferred the whole of Suðreyjar to Scotland in exchange for a very large sum of money The Treaty expressly preserved the status of the rulers of Suðreyjar; the MacRory lands excepting Bute Arran and Jura became the Lordship of Garmoran a quasi-independent crown dependency rather than an intrinsic part of Scotland Following this the Norse longhouses were gradually abandoned in favour of new Blackhouses and a new parish church was built at Howmore for South Uist