Browne was admitted as a member of the
Honourable Artillery Company in 1622 and was an officer in the part-time
London Trained Bands (LTBs). When the LTBs were expanded in April 1642, Browne was 1st
Captain of the Orange Regiment. By mid-September, after the
Civil War had broken out, he was organising a regiment of
dragoons recruited in London, of which he became
Colonel. He helped to disarm Royalists in Kent and then served under Sir
William Waller at the seizure of
Winchester in December. Browne's Dragoons were in action at
Brill in January 1643. In July 1643, Browne was given an independent command, leading Mainwaring's Redcoats and the Green Auxiliaries of the LTBs with detachments of horse and dragoons to break up an assembly of Royalists at
Sevenoaks in Kent. The Royalists retreated to
Tonbridge where there was a three-hour skirmish on 24 July, when they were driven out of town and 200 were captured. It had become the practice for regiments drawn from the LTBs to serve for short periods with the Parliamentarian field armies. In December 1643 Parliament appointed Browne
Sergeant-Major-General to command a City brigade consisting of the White and Yellow Regiments to reinforce Waller's army besieging
Arundel Castle. The two regiments marched out on 4 and 5 January 1644 with a number of cannon, but heavy snow delayed their march for several days at
Guildford, and they did not reach
Petworth until 29 January, after Arundel had fallen. Here Browne fortified
Petworth House in case
Lord Hopton's Royalist army threatened. The brigade remained there for two months before moving to
Midhurst on 20 March and then joining Waller's army on 27 March. Waller and Hopton manoeuvred and skirmished for two days, with Waller's army camped in the fields at
Cheriton. Then on 29 March Waller sent skirmishers including some of Browne's men into Cheriton Wood on Hopton's left. Hopton drove them out, but his horse attacked without orders, precipitating a general engagement (the
Battle of Cheriton). A cavalry battle took place in the space between the wings of foot, the London brigade having to drive back several Royalist probes in their direction. The Royalist cavalry lost heavily, and in the afternoon Browne led the foot back into Cheriton Wood as Hopton's army began to retreat. On 6 April Browne's City Brigade was engaged at
Bishop's Waltham, where they forced the surrender of the fortified
Bishop's Palace. The Londoners were now anxious to return home, and the two regiments left without orders, returning to the city as heroes on 14 April. Without the City Brigade Waller had to shut down operations. 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. The Royalist army having disengaged and moved west, Browne was sent to capture Greenland House near
Henley-on-Thames, under his original orders, and then moved to
Reading. Ordered to join Waller at
Abingdon-on-Thames, he objected that he had only 'three broken regiments of London auxiliaries, not above 800 in all' to hold Reading. In fact, he had fallen out with Waller and threatened to resign if forced to accept the latter's orders. In the end Waller left for London and Browne was put in command of the whole force at Abingdon, marching in with his brigade on 15 August. He and his troops were not involved in the
Second Battle of Newbury in October, but as Governor of Abingdon, Browne kept up active skirmishing against the Royalist stronghold of Oxford during the winter. In the summer of 1645 he participated in the
Second Siege of Oxford, and in September had to put down a serious clash between the garrison of
Aylesbury and other Parliamentarian troops. He was again active in the final
Third Siege of Oxford in 1646 and continued as Governor of Abingdon until the end of the First Civil War later that year. ==Political career==