In February 1643 Sir William Waller, at that time the most successful of the parliamentarian generals, was appointed parliamentarian commander of the Western Association based in Bristol and responsible for Parliament's war effort in the surrounding counties including Gloucestershire and Worcestershire. In March 1643 he advanced northwards.  Gloucester which was being blockaded on the west side by a Welsh force under Lord Herbert. At the Battle of Highnam on 24 March Waller defeated Herbert and pursued him into Wales. He was unable to bring Herbert to battle again but prevented him from re-grouping.  The parliamentarian Governor of Gloucester, Colonel Edward Massey took the opportunity to seize Tewkesbury.

Shortly afterwards a royalist force of about 2,000 men under Prince Maurice arrived and quickly drove the parliamentarians out of Tewkesbury.  As there was no bridge over the Severn (although there was one over the Avon) Maurice crossed the Severn by means of a bridge of boats and pursued Waller, nearly trapping him in Wales.  However Waller captured a royalist ship at Chepstow and used it to transport his artillery and infantry to the east side of the Severn from where they returned to Gloucester.  With his cavalry he made a dash through the royalist lines back to Gloucester.

While Waller was reassembling his troops, Massey drove out the remaining royalists from Tewkesbury and destroyed Maurice’s bridge of boats hoping to isolate Maurice on the west side of the Severn.  To do that the parliamentarians needed to take Upton Bridge and Waller and Massey advanced out of Tewkesbury for that purpose.  However, Maurice beat them to it, crossed Upton Bridge and turned south.  The opposing forces met just north of Ripple village on 13 April 1643, where Waller’s force was defeated.

Maurice was unable to follow up his victory because he was called away to assist in the relief of Reading.  This left Waller in control of the Severn Valley south of Worcester.  He advanced to Hereford in an attempt to sever the royalist communications with Wales.  Hereford surrendered to him on 25 April but Waller had insufficient men to garrison it and on 20 May withdrew to Gloucester.  On 29 May he made an attempt against Worcester.  This is known as the first siege of Worcester but was in reality a two day assault.  Waller’s attacks were repulsed and by 31 May he was in difficulties.  Firstly, the royalist general Hopton was advancing from the West Country and Waller was urgently needed back in Bristol. Secondly Waller learnt that Prince Maurice was on his way back and making for Upton which would have put royalist forces behind him.  Waller had no alternative but to withdraw to Gloucester and then to Bristol.