Leslie's reputation, guile and discretion were frequently noted by contemporary observers including the English officer John Aston and intellectual, Sir Cheney Culpeper, who both commented on his qualities in their writings. His reputation was well earned and he took Edinburgh Castle without the loss of a single man. He had also by now amassed a considerable fortune and was able to live in a manner befitting a commander-in-chief, even when in the field. In the First Bishops' War, Leslie marched his army to Dunse Law where he encamped and awaited the arrival of the Royalist forces. Rather than fight them when they arrived, Leslie invited the Royalist officers to dinner before allowing them to inspect his army. Having seen they were out-classed by the Army of the Covenant, the Royalists chose to retire rather than to engage Leslie's superior forces. In the Second Bishops' War, Leslie conducted a brilliant campaign in the North of England, overwhelming the Royalists at the Battle of Newburn. From there he took Newcastle with ease putting pressure on the King to come to a treaty with the Scottish Covenanters. Thus followed the treaty of London.