Solemn League and Covenant
The Solemn League and Covenant was an agreement between the Scottish Covenanters and the leaders of the English Parliamentarians in 1643 during the First English Civil War, a theatre of conflict in the Wars of the Three Kingdoms. On 17 August 1643, the Church of Scotland accepted it and on 25 September 1643 so did the English Parliament and the Westminster Assembly.
English Parliament (First Civil War)
At the time, the Protestant leaders of the English Parliament were in conflict with King Charles I. Fearing Irish Catholic troops could join the Royalist army, Parliament requested the aid of the Scots. The Presbyterian Covenanters promised their aid, on condition that the Scottish system of church government was adopted in England. This was acceptable to the majority of the English Long Parliament, as many MPs were Presbyterians, while others preferred allying with the Scots rather than losing the Civil War.After some haggling a document called "The Solemn League and Covenant" was drawn up. This was in effect a treaty between the English parliament and its Scottish counterpart for the preservation of the reformed religion in Scotland, the reformation of religion in England and Ireland "according to the word of God and the example of the best reformed churches", and the "extirpation of popery prelacy". It did not explicitly mention Presbyterianism, and included some ambiguous formulations which left the door open to the English Independents, another strong faction on the English Parliamentary side, particularly in the parliamentary armies. It was subscribed to by many in England, Scotland, and Ireland, approved by the English Long Parliament, and, with some slight modifications, by the Westminster Assembly of Divines.
However, not all those on the English Parliamentarian side were happy with this arrangement and some, like John Lilburne, chose to leave the parliamentary armies rather than take the oath prescribed in the Act enforcing the Solemn League and Covenant.
The agreement meant that the Covenanters sent another army south to England to fight on the Parliamentarian side in the First English Civil War. When the Scots army entered England by invitation of the English Parliament in January 1644 the Parliamentary Committee of Safety was replaced by an ad hoc committee representative of both kingdoms which, by parliamentary ordinance of 16 February, was formally constituted the Committee of Both Kingdoms. Its object was the management of peace overtures to, or making war on, King Charles I. The Scots withdrew from the committee after the end of the First Civil War, although it continued to sit and from then on was known as the Derby House Committee.