In June 1644 Parliament gave Browne a commission as Major-General for the counties of Oxfordshire, Buckinghamshire and Berkshire with the task of reducing the Royalist garrisons, and assigned him a brigade consisting of the Red, White and Blue Auxiliaries of the LTBs, all understrength. It was learnt that the King's army from Oxford was moving eastwards and threatening the Parliamentarian Eastern Association, so Browne was directed into Hertfordshire to protect these counties. He was joined by the Essex and Hertfordshire Trained Bands. By the time his force assembled at Barnet, he was too late to help Waller, who was defeated by the Royalists at the Battle of Cropredy Bridge on 29 June. When he joined Waller at Towcester on 2 July, Waller's dispirited London brigade assumed that Browne's had been sent to relieve them, and they set up a chant of 'Home, Home!' The Essex and Hertfordshire men were also deserting, and on 6 July they wounded Browne in the face when he confronted them.