Anglo-Scottish war (1650–1652) in the context of "English Civil War"

The Tender of Union was a declaration of the Parliament of England during the Interregnum following the War of the Three Kingdoms stating that Scotland would cease to have an independent parliament and would join England in its emerging Commonwealth republic.

The English parliament passed the declaration on 28 October 1651 and after a number of interim steps an Act of Union was passed on 26 June 1657. The proclamation of the Tender of Union in Scotland on 4 February 1652 regularised the de facto annexation of Scotland by England following the English victory in the recent Anglo-Scottish war. Under the terms of the Tender of Union and the final enactment, the Scottish Parliament was permanently dissolved and Scotland was given 30 seats in the Westminster Parliament. This act, like all the others passed during the Interregnum, was repealed by both Scottish and English parliaments upon the Restoration of monarchy under Charles II.

The Wars of the Three Kingdoms were a series of conflicts fought between 1639 and 1653 in the kingdoms of England, Scotland and Ireland, then separate entities in a personal union under Charles I. They include the 1639 to 1640 Bishops' Wars, the First and Second English Civil Wars, the Irish Confederate Wars, the Cromwellian conquest of Ireland and the Anglo-Scottish War of 1650–1652. They resulted in the execution of Charles I, the abolition of monarchy, and founding of the Commonwealth of England, a unitary state which controlled the British Isles until the Stuart Restoration in 1660.

Political and religious conflict between Charles I and his opponents dated to the early years of his reign. While the vast majority supported the institution of monarchy, they disagreed on who held ultimate authority. Royalists generally argued political and religious bodies were subordinate to the king, while most of their Parliamentarian opponents backed a limited form of constitutional monarchy. This was worsened by differences over religion and religious freedom. Reformed Protestants such as the English Puritans and Scottish Covenanters opposed the changes Charles tried to impose on the Protestant state churches of England and Scotland. In Ireland, the only one with a Catholic majority, the Irish Confederates wanted an end to anti-Catholic discrimination, greater self-governance, and a reversal of land grants to Protestant settlers.

The Bishops' Wars were two separate conflicts fought in 1639 and 1640 between Charles I and his Covenanter opponents in Scotland. They were the first of the Wars of the Three Kingdoms, which also include the First and Second English Civil Wars, the Irish Confederate Wars, and the 1650 to 1652 Anglo-Scottish War.

In 1637, Charles I, then king of both Scotland and England, imposed changes in religious practice on the Church of Scotland. These were strongly opposed by many Scots, leading to the signing of a National Covenant in 1638, pledging to prevent their implementation. The General Assembly of the Church of Scotland then expelled bishops, turning a religious dispute into a struggle for political supremacy. The new Covenanter government raised an army to prevent Charles using force to restore his authority.