wrote to the Earl of Shrewsbury at Sheffield Castle to be vigilant. Matthew Stewart, Regent Lennox died from a gunshot wound after a struggle on the streets of Stirling. On 18 November 1571, the new Regent, John Erskine, Earl of Mar, sent Morton with Robert Pitcairn, Commendator of Dunfermline and James MacGill of Nether Rankeillour to negotiate with Elizabeth's representative Henry Carey, 1st Baron Hunsdon, Governor of Berwick upon Tweed. Mar wanted English help to capture Edinburgh Castle from Sir William Kirkcaldy of Grange who held it for Mary. Regent Mar hoped that Morton could arrange for 12 cannons, 3000 foot soldiers, and wages for the 800 Scottish foot soldiers and 200 horsemen already in the field. Morton was instructed to offer six hostages to England from the sons of the nobility who supported James VI. He also discussed returning the Earl of Northumberland, who was a fugitive after the failed Rising of the North, to England. A week later Morton wrote to Hunsdon with the same request, urging an attack in winter because the Castle was vulnerable when the Nor' Loch was frozen. Hunsdon replied that Elizabeth still hoped for a peaceful settlement, but he would send an estimate of the expedition's cost to Elizabeth. Morton received a token payment. The English rebels were handed over. The treaty for military aid was still not finalised when Mar died at Stirling in October 1572. On 24 November 1572, a month after the death of Regent Mar, Morton, who had been the most powerful noble during Mar and Lennox's rule, at last reached the object of his ambition by being elected regent. As Regent of Scotland, Morton expected the support of England and Elizabeth, and a week after his election, he wrote to William Cecil, Lord Burghley following his discussions with the English ambassador Henry Killigrew;The knowledge of her Majesty's meaning has chiefly moved me to accept the charge (the Regency), resting in assured hope of her favourable protection and maintenance, especially for the present payment of our men-of-war their bypast wages, "without the quhilk I salbe drevin in mony great inconvenientis." In many respects Morton was an energetic and capable ruler. His first achievement was the conclusion of the civil war in Scotland against the supporters of the exiled Mary. In February 1573 he effected a pacification with George Gordon, 5th Earl of Huntly, the Hamiltons and other Catholic nobles