Thomas Prior married (1) Jemima Dickson at Millbrook, Southampton, England on 28 November 1812.¹⁾ Jemima's father was presumably also in the military forces as he was Captain Dickson Esq. of Prospect House, Southampton. As her family home indicates, her family were comfortably off. Her brother reinforces this assumption as, when he died in the 1870s, he left bequests of several thousands of pounds.²⁾ Jemima had been married for a nearly five years when, on 5 November 1817, aged 26, she died, and was buried at, Dover.³⁾

Jemima and Thomas had three children: Jemima Frances Sophia; William Amherst born in London in 1814 or 15 and dying when still a baby; and Louisa Elizabeth Catherine.⁴⁾

TLM-P related the story of the marriage as told to him by his step-sister Jemima. She told him that, when their father was 19 years old, he saw Jemima Dickson in the street and declared to his companion that 'if ever I marry she will be my wife'. They became acquainted but then he was ordered to Spain with the army; they married on his return some 3 or 4 years later. She brought with her to the marriage £5,000, including £1,000 in hand, but they soon spent it - in 2017 values, they went through around £337,900 (about $611,000). This is all the more likely if his daughter Jemima is correct in believing that he was 'great friends' with the spendthrift Duke of York and his mistress Mary Anne Clarke. By 1815, they were in 'great straits', and struggled to find around £300 needed to buy equipment before the battle of Waterloo. After that victory, Thomas had the altercation with the Frenchman which led to him being put on half-pay. The marriage was in such trouble that, when he left Boulogne suddenly and at the same time as a widow, it was thought they had run away together - something Thomas denied. A separation was proposed but, on her return to England, Jemima died from a fever. Their mother's maid was put in charge of the two young daughters. The widowed Thomas asked a family friend to 'look out a young lady with money for the widower'. She found him one, but her father forbade the marriage. Thomas then was introduced to Eliza Skynner, whom he soon married. All this took place just over a year after Jemima's death!⁵⁾