With the general course of the Great Rebellion we are not here concerned. It is important for our purpose to notice that it affected Scotland in two ways. The course of events converted, on the one hand, the Episcopalian party into a Royalist party, and placed at its head the Covenanter, Montrose. On the other hand, the National Covenant was transformed into the Solemn League and Covenant, which had for its aim the establishment of Presbytery in England as well as in Scotland. This "will o' the wisp" of covenanted uniformity led the Scottish Church into somewhat strange places. As early as January, 1643, Montrose had offered to strike a blow for the king in Scotland, but Charles would not take the responsibility of beginning the strife. In August negotiations began for the extension of the covenant to England. The Solemn League and Covenant, which provided for the abolition of Episcopacy in England, was adopted by the Convention of Estates at Edinburgh on August 17th, and in the following month it passed both Houses of Parliament in England, and was taken both by the House of Commons and by the Assembly of Divines at Westminster. Its only ultimate results were the substitution in Scotland of the Westminster Confession of Faith, Catechisms, and Directory for Public Worship, in place of the older Scottish documents, and the approximation of Scottish Presbytery to English Puritanism, involving a distinct departure from the ideals of the Scottish Reformation, and the introduction into Scotland of a form of Sabbatarianism which has come to be regarded as distinctively Scottish, but which owes its origin, historically, to English Nonconformity.[89] Its immediate effects were the short-lived predominance of Presbytery in England, and the crossing of the Tweed, in January, 1644, by a Scottish army in the pay of the English Parliament. The part taken by the Scottish army in the war was not unimportant. In April they aided Fairfax in the siege of York; in July they took an honourable share in the battle of Marston Moor; they were responsible for the Uxbridge proposals which provided for peace on the basis of a Presbyterian settlement. In June, 1645, they advanced southwards to Mansfield, and, after the surrender of Carlisle, on June 28th, and its occupation by a Scottish garrison, Leven proceeded to Alcester and thereafter laid siege to Hereford, an attempt which events in Scotland forced him to abandon. Finally, in May, 1646, the king surrendered to the Scottish army at Newark, which had been invested by Leven since the preceding November.