Old Aberdeen was an important political, ecclesiastical and cultural centre since the Late Middle Ages. In the 1630s the Covenanters challenged the Doctors of Aberdeen by holding a meeting in Muchalls Castle and responding to certain letters issued by the doctors, thus setting the stage for the first battle of the Bishops' Wars, when William Keith, 7th Earl Marischal and the Marquess of Montrose led a Covenanter army of 9,000 men over the Causey Mounth to attack forces at the Bridge of Dee, effectively gaining control of Old Aberdeen.