 William Maitland of Lethington (and Sir James Balfour) were publicly accused of Darnley's murder by Crawford; Balfour escaped, but Lethington was imprisoned and was released by William Kirkcaldy of Grange, commander in Edinburgh Castle, which subsequently became the fortress of Mary's cause during the Lang Siege in the ensuing civil war.Crawford planned the assault and led a force of 150 men in the early hours of 2 April 1571 that scaled the cliffs and embattlements to expel the castle garrison loyal to Catholic Queen Mary from Dumbarton Castle.In this task he was assisted by John Cunningham of Drumquhassle, Matthew Douglas of Mains (both also retainers of the Earl of Lennox) and a traitor from the castle garrison called Robertson.