 The reason it was awakened was that in the summer of 1174 King William had invaded northern England, and on 13 July, having been caught underprotected during a siege at Alnwick, was captured and taken into English custody.The capture was disastrous for the king, leading to a revolt by Gilla Brigte, Lord of Galloway, and to many of William's discontented subjects "ruthlessly" slaying "their English and French neighbours" and perpetrating a "most wretched and widespread persecution of the English both in Scotland and Galloway", that is, of the English and French-speaking settlers William and his predecessors had planted around the castles and towns of his Gaelic-speaking territories in order to increase royal authority.Worse still, and more significantly for Jocelin, in the following year King Henry II of England forced William to sign the Treaty of Falaise, a treaty which made William Henry's vassal specifically for Scotland and sanctioned the subordination of the kingdom's bishoprics to the English church.