The siege of Oxford comprised the English Civil War military campaigns waged to besiege the Royalist controlled city of Oxford, involving three short engagements over twenty-five months, which ended with a Parliamentarian victory in June 1646.
The first engagement was in May 1644, during which King Charles I escaped, thus preventing a formal siege. The second, in May 1645, had barely started when Sir Thomas Fairfax was given orders to stop and pursue the King to Naseby instead. The last siege began in May 1646 and was a formal siege of two months; but the war was obviously over and negotiation, rather than fighting, took precedence. Being careful not to inflict too much damage on the city, Fairfax even sent in food to the King's second son, James, and was happy to conclude the siege with an honourable agreement before any further escalation occurred.
Oxford during the civil war
The creation of the King's Oxford Parliament in January 1644 placed Oxford at the centre of the Cavalier cause and the city became the headquarters of the King's forces. This had advantages and disadvantages for both parties; although the majority of citizens supported the Roundheads, supplying the Royalist court and garrison gave them financial opportunities. The location of Oxford gave the King the strategic advantage in controlling the Midland counties but the disadvantages of the city became increasingly manifest. Despite this, any proposals to retreat to the southwest were silenced, particularly by those enjoying the comforts of university accommodation. The King was at Christ Church and the Queen at Merton. The executive committee of the Privy Council met at Oriel; St John's housed the French ambassador and the two Palatine princes Rupert and Maurice; All Souls, New College, and St Mary's College housed respectively the arsenal, the magazine and an ordnance factory; while the mills in Osney became a powder factory. At New Inn Hall, the requisitioned college plate was melted down into 'Oxford Crowns', and at Carfax, there was a gibbet. University life continued, although somewhat restricted and disturbed; the future kings Charles II (then Prince of Wales) and James II (then Duke of York) were given Master of Arts degrees, as were many others for non-academic reasons. Throughout, both sides employed poor strategies and suffered from weak intelligence, and there was less animosity between the sides than is usual in such wars.
First siege (1644)
Late in May 1644 Edmund Ludlow joined Sir William Waller at Abingdon to blockade Oxford. According to Sir Edward Walker's diary, on 27 May Waller attempted to cross the Isis at Newbridge, but was defeated by Royalist dragoons. The following day, the Earl of Essex Earl of Essex and his army forded the river at Sandford-on-Thames, halting on Bullingdon Green in full view of the city. Whilst the main army marched on to Islip to make quarters there, the Earl of Essex and a small party of horse came within cannon shot to make a closer inspection of the place. For a large part of 29 May, various parties of Parliamentarian horse troop went up and down Headington Hill and had a few skirmishes near the ports, although little damage was made on either side—the work at St Clement's Port made three or four great shot at them, driving them back to the main body of troops. The King, being at that time on the top of Magdalen Tower, had a clear view of the troops' manoeuvres.
On 30 May and 31 May the Parliamentarians made unsuccessful attempts to cross the River Cherwell at Gosford Bridge, and Earl of Cleveland Thomas Wentworth made a demonstration with 150 horse troops towards Abingdon, where Waller had 1,000 foot and 400 horse troops. Entering the town, Cleveland captured forty prisoners, but was pursued so heavily they escaped, and although he killed the commander of their party, the Royalists lost Captains de Lyne and Trist, with many more wounded.