due to fears of high casualties. By 11 August, the Royalist trenches were dug and the artillery prepared, despite Massie's attempts to disrupt work with musket fire. With this work done, there was no way out for the Parliamentarians; the only hope was to delay the Royalists long enough for a relief army to arrive. To this end, Massie ordered raids under the cover of darkness, with James Harcus, his second-in-command, leading a raid on the artillery trenches. In revenge the Royalists attacked the east of the city, but were driven off by cannon fire. 12 August saw more raids, this time during the day, which cost the Royalists 10 men and a supply depot, with no Parliamentarian losses. Despite this, the assaults did not disrupt Royalist preparations and by the evening they were able to start bombarding the town. By 24 August, the Royalists, suffering from shortfalls in their stocks of gunpowder and cannonballs, remained unable to breach the walls. Essex, in the meantime, had been urgently preparing his army, which thanks to disease, indiscipline and desertion numbered less than 6,000 infantry and 3,500 cavalry. This was not a force strong enough to defeat the Royalists, and so he demanded an extra 5,000 soldiers; Parliamentarians in London responded by mobilising a brigade of the London Trained Bands, which provided an additional 6,000 men. Taking into account additional problems and desertions, the eventual force was 9,000-foot soldiers and 5,000 cavalry. After being mustered on Hounslow Heath, the army began marching towards Aylesbury, arriving on 28 August. This force was formally mustered on 30 August, and after being reinforced by Lord Grey on 1 September at Brackley, marched to Gloucester. On 5 September, with heavy rain falling, the Parliamentarian army reached the town and camped on Prestbury Hill, immediately outside it; their presence forced the Royalists to abandon the siege given that neither army, wet and exhausted, was in a state to seek battle. Pursuit Charles's cautious failure to directly assault the town, putting a higher priority on minimising losses than on victory, had cost the Royalists dearly; while claims for their number of dead and wounded men ranged from 1,000 to 1,500, only around 50 people inside the city were killed. Essex's force, on the other hand, was in relatively good shape; its one issue was the lack of supplies. If he stayed in the Severn Valley, Essex would be