Charles I inherited a settlement in Scotland based on a balanced compromise between Calvinist doctrine and episcopal practice. Lacking the political judgement of his father, he began to upset this by moving into more dangerous areas. Disapproving of the 'plainness' of the Scottish service he, together with his Archbishop of Canterbury, William Laud, sought to introduce the kind of liturgical practice in use in England. The centrepiece of this new strategy was the Prayer Book of 1637, a slightly modified version of the Anglican "Book of Common Prayer". Although this was devised by a panel of Scottish bishops, Charles' insistence that it be drawn up in secret and adopted sight-unseen led to widespread discontent. When the Prayer Book was finally introduced at St Giles Cathedral in Edinburgh in mid-1637 it caused an outbreak of rioting, which, starting with Jenny Geddes, spread across Scotland. In early 1638 the National Covenant was signed by large numbers of Scots, protesting at the introduction of the Prayer Book and other liturgical innovations that had not first been tested and approved by free Parliaments and General Assemblies of the Church. In November 1638, the General Assembly in Glasgow, the first to meet for twenty years, not only declared the Prayer Book unlawful, but went on to abolish the office of bishop itself. The Church of Scotland was then established on a Presbyterian basis. Charles' attempt at resistance to these developments led to the outbreak of the Bishops' Wars. In the ensuing civil wars, the Scots Covenanters at one point made common cause with the English parliamentarians—resulting in the Westminster Confession of Faith being agreed by both. This document remains the subordinate standard of the Church of Scotland, but was replaced in England after the Restoration.