A Parliamentarian army of around 28,000 under Oliver Cromwell defeated a largely Scottish Royalist force of 16,000 led by Charles II of England.

Thomas Fairfax emerged for a moment from his retirement to organize the Yorkshire levies, and the best of these as well as of the Lancashire, Cheshire and Staffordshire militias were directed upon Warrington, which Harrison reached on 15 August, a few hours in front of Charles's advanced guard.

Lambert too, slipping round the left flank of the enemy, joined Harrison, and the English fell back (16 August), slowly and without letting themselves be drawn into a fight, along the London road.

[4] Cromwell meanwhile, leaving George Monck with the least efficient regiments to carry on the war in Scotland, had reached the river Tyne in seven days, and thence, marching 20 miles a day in extreme heat with the country people carrying their arms and equipment, the regulars entered Ferrybridge on 19 August, at which date Lambert, Harrison and the north-western militia were about Congleton.

It seemed probable that a great battle would take place between Lichfield and Coventry on or just after 25 August and that Cromwell, Harrison, Lambert and Fleetwood would all take part in it but the scene and the date of the denouement were changed by the Royalists' movements.

Shortly after leaving Warrington the young king had resolved to abandon the direct march on London and to make for the Severn valley, where his father had found the most constant and the most numerous adherents in the first war, and which had been the centre of gravity of the English Royalist movement of 1648.

The military quality of the Welsh border Royalists was well proved, that of the Gloucestershire Presbyterians not less so, and, in basing himself on Gloucester and Worcester as his father had done on Oxford, Charles II hoped, naturally, to deal with the Independent faction minority of the English people more effectually than Charles I had earlier dealt with the majority of the people of England who had supported the Parliamentary cause.

[4] Charles arrived at Worcester on 22 August and spent five days in resting the troops, preparing for further operations, and gathering and arming the few recruits who came in.

[5] Cromwell, the lord general, had during his march south thrown out successively two flying columns under Colonel Robert Lilburne to deal with the Lancashire Royalists under the Earl of Derby.

Lilburne entirely routed a Lancashire detachment of the enemy on their way to join the main Royalist army at the Battle of Wigan Lane on 25 August and as affairs turned out Cromwell merely shifted the area of his concentration two marches to the south-west, to Evesham.

In the action which followed Massey was severely wounded and he and his men were forced to retreat northwards along the west bank of the Severn towards the river Teme and Worcester.

[4][6] On 30 August Cromwell delayed the start of the battle to give time for two pontoon bridges to be constructed, one over the Severn and the other over the Teme, close to their confluence.

Lilburne from Lancashire and Major Mercer with the Worcestershire horse were to secure Bewdley Bridge, 12 miles (19 km) north of Worcester and on the enemy's line of retreat.

Charles II, from his vantage point on top of Worcester Cathedral's tower, realised that an opportunity existed to attack the now-exposed eastern flank of the Parliamentary army.

[16] This cavalry force was composed of the few Midland English Royalists who had rallied to Charles II, and largely consisted of Lord Talbot's troop of horse.

Even the country people brought in scores of prisoners, for the Royalist officers and men alike, stunned by the suddenness of the disaster, offered no resistance.

[22] In announcing the Worcester victory of the day earlier, Cromwell's 4 September despatch to William Lenthall, the Speaker of the House of Commons, has become famous: "The dimensions of this mercy are above my thoughts.

The expression "crowning mercy" is frequently linked to the battle as it heralded the end of the English Civil War by completely destroying the last major Royalist army.

"Your new raised forces", he wrote to the Rump Parliament, "did perform singular good service, for which they deserve a very high estimation and acknowledgement".

[25] Prior to the battle King Charles II contracted the Worcester Clothiers Company to outfit his army with uniforms but was unable to pay the £453.3s bill.

John Adams wrote that he was "deeply moved" but disappointed at the locals' lack of knowledge of the battle, and gave the townspeople an "impromptu lecture", The people in the neighborhood appeared so ignorant and careless at Worcester that I was provoked and asked "And do Englishmen so soon forget the ground where liberty was fought for?