 Complete the following phrase:  Edward III himself came north to command his army, and laid siege to Berwick-upon-Tweed. However, a temporary truce was declared with the stipulation that if not relieved within a set time, Sir Alexander Seton, the governor, would deliver the castle to the English. Douglas raised an army to relieve the beleaguered defenders of Berwick. As a feint to draw the English away he invaded Northumberland, but was forced to return to Berwick when the English refused to be lured. On 19 July, Edwards army took positions at the summit of 