Derby then joined the retreat northwards with Leslie, the Earl of Lauderdale, Lord Talbot and others. They were attacked by Colonel Blundell, but managed to make their escape. Soon afterwards, however, they fell in with another skirmish and were captured. A Lancashire captain named Oliver Edge was riding by himself to see what had become of the 'forlorn,' when he noticed a party of horse in the field behind him. Fearing they were enemies he hastened back towards his regiment; when to his surprise all the horsemen dismounted and surrendered themselves prisoners. The Earls of Derby and Lauderdale were the most important of those captured. Edge gave the prisoners quarter but his action was over-ruled by the Parliament through no fault of his own. Derby afterwards wrote of Edge as "one that was so civil to me, that I and all that love me are beholden to him." The Earl with some other prisoners was carried to Chester Castle.[236] After the battle of Wigan Lane, Lilburne sent up Lieutenant Turner to London with letters to the House of Parliament which were read on August 30th. After hearing the letters Turner was called in to give an account of the battle; and the House made him a present of £100, at the same time voting to Lilburne the sum of £500 and lands to the yearly value of £200. This was to be raised out of some delinquent's lands, and was in satisfaction of two former votes of £1,000 each which remained undischarged. The Sunday after the battle (August 31st) was named as a public thanksgiving.[237] The Earl of Derby's papers were referred to the Council of State to see whether they contained anything of importance (August 30th); for so hasty had been his flight from Wigan that all his baggage, including his cloaks with his Orders, fell into Lilburne's hands. On the following Monday Sir Harry Vane, the younger, reported to the House that papers of great importance had been found in the Earl's hampers, and as a result of their examination the Council of State decided on September 10 to represent to Parliament that Derby was a fit person to be brought to trial and made an example of justice; and that he should be tried by court-martial at Chester.[238] Parliament made the required vote on the following day, September 11th. The irreconcilable hostility of the Earl to the Parliament, his high rank, and especially his prominent part in the last campaign, rather than his personal character, probably decided the Council of State to deal hardly with him. He was not a dangerous man. But it was thought necessary that an example should be made. Much has been written by royalists of the perfidy of putting him on trial for his life after quarter had been given; but Derby must have known that Edge's promise was liable to be over-ruled by a higher authority; and in any case it could have made little difference, for if Derby and his companions had not surrendered at Newport, they must have been captured during the next few days.