The long-running feud between Charles I and parliament tipped into open war in August 1642, after rebellions in Scotland and then Ireland precipitated discontent with royal autocracy. Crucially, the Parliamentarian power base was in the wealthy southeast; a royal attempt to move on London was repulsed at Turnham Green. However, the first year of the war was broadly favourable for the Royalist cause. After the inconclusive first battle at Edgehill, significant advances were achieved from Royalist strongholds in Cornwall and Oxford. In the north, the Parliamentarians prevailed at Winceby and Whalley, but, outnumbered, were overcome at Adwalton Moor. The tide began to turn in summer 1643, when the Royalists, after capturing Bristol, were forced to lift their siege of Gloucester. The Parliamentary general, the Earl of Essex, demonstrated his troops could withstand Prince Rupert’s cavalry at Newbury in September, once more safeguarding London, while Cromwell was trialling his ‘Ironsides’ in the north.