 In 1648, Henrietta Maria sent him to Scotland to further 'the engagement,' and to persuade his countrymen to receive the Prince of Wales, whom she wished to take part in the effort for the deliverance of the king.He first tried to induce Argyll and the dominant party in the church to support the resolutions of the Scottish estates, but, failing in this, he took counsel with the Duke of Hamilton and his friends, and in May, he returned to the continent with letters from them formally inviting the prince to Scotland.Among those who gathered round Charles II at the Hague immediately after his father's death, Lord Byron mentions "old William Murray, employed here by Argyll."