However, sometime about 1807 Thomas Allen formed a connection with a much younger woman, Ann, who was born in Hackney about 1790, and by whom he had five illegitimate children between 1808 and 1829. Her surname is usually given as Salmon (as she had a niece of that name living with her in 1851) but the death certificates of several of her children show it as Burton. The first child, William (died 1878), who used the surname MacGarrow, claimed to have been born in Glamorganshire or Wales but his baptism and the exact whereabouts of Thomas and Ann at this time have not been determined. It is said that from 1816 to 1829 Thomas was based at Boulogne, ‘a safe refuge for English debtors’. He certainly had increasing financial problems and in February 1817 he unsuccessfully appealed to the former Lord Chancellor, Lord Erskine, for help with the possible sale of some of the property held in trust under his marriage settlement. A last minute attempt to come to an arrangement about it failed and on 17 January 1818, as the result of an action in the Court of Kings Bench against Thomas and his son John (in a plea of debt for £300 and damages by James Barstow), Thomas was imprisoned for debt in the Fleet Prison. He was released by order of the Court for Relief of Insolvent Debtors on 20 December 1819 but continued to live in fear of his creditors.