Of Yorkshire origin, the Thorold family had been settled at Marston, near Grantham, since the 14th century. Anthony Thorold’s father, a merchant of the staple, was sheriff of Lincolnshire in 1558-9 and a leading figure at Grantham. Of Thorold’s own early career nothing is known save that it included the professional training which equipped him for legal office. His first appointment, as recorder of Grantham, he appears to have received soon after 1550. In 1581 he explained to his fellow justices how throughout his time as recorder the borough had delegated its subsidy assessment to certain approved persons, a task which, he added, ‘for almost 30 years past either Mr. Carre [presumably Robert Carr] and I, or my father and I whilst he lived, have from time to time executed’. That the recordership was not more quickly followed by Thorold’s election to Parliament may reflect the competition for seats between townsmen and nominees. When his own turn came in the Parliament of 1558 he could doubtless add to his municipal standing the support of the 2nd Earl of Rutland: it was Rutland who was to procure him a seat for Lincoln in the following Parliament as well as the recordership of the city. In August 1558 he was named an executor by Thomas Grantham, who had just completed his year as mayor of Lincoln.
Adjudged ‘earnest in religion’ in 1564, Thorold was to remain active in Lincolnshire until his death on 26 June 1594. He rebuilt Marston Hall, where his descendants still live.