The next day however, Rupert chose to engage them even though he was outnumbered. In the resulting Battle of Marston Moor, all of Fairfax's army and half the Scots fled. However, Manchester's infantry and especially the Eastern Association cavalry under Cromwell stood firm. Cromwell's cavalry - aided by Covenanter regiments - first drove off Royalist cavalry on their side of the field. Showing discipline they rallied beyond the Royalist forces and then attacked the Royalist cavalry under Goring on the other side. routed the Royalists from the field. The siege of York was resumed and the city fell to Parliamentarians on 16 July.