Scotland tips the balance
On 14 June 1645, the Battle of Naseby in Northamptonshire effectively ended Charles I's hopes of winning the English Civil War. The Parliamentary New Model Army under Sir Thomas Fairfax and Oliver Cromwell destroyed the main Royalist field army, capturing the king's baggage, his personal correspondence, and five thousand prisoners. For Scotland, Naseby was a pivotal moment in a conflict that would engulf the entire British Isles.
Scotland's role in the English Civil War was decisive but often overlooked. In 1643, the Scottish Covenanters signed the Solemn League and Covenant with the English Parliament, promising to send an army south in exchange for a commitment to impose Presbyterianism across Britain. In January 1644, a Scottish Covenanter army of over twenty thousand men crossed the border under the Earl of Leven. Their presence transformed the military balance. At the Battle of Marston Moor in July 1644, the combined Scottish and Parliamentary forces inflicted a catastrophic defeat on the Royalists, effectively ending the king's control of northern England.
By the time of Naseby, the Scots had tied down Royalist forces and freed the New Model Army to strike the decisive blow. The Covenanter contribution was military, political, and moral — their intervention gave Parliament the manpower and the momentum it needed. Without the Scottish army, the course of the Civil War might have been very different.
But the consequences for Scotland were devastating. Having helped Parliament defeat the king, the Scots then recoiled from the increasingly radical direction of English politics. When Parliament executed Charles I in 1649, the Scots were appalled — they had fought to restrain the king, not to kill him. They proclaimed Charles II and were invaded by Cromwell for their trouble. Scotland's reward for tipping the balance of the English Civil War was conquest, occupation, and a decade of military rule. It was a bitter lesson in the dangers of entanglement with English affairs.