As the son of one of the most prominent figures in early 15th-century Newcastle-upon-Tyne, Thomas Hebburn was assured of a promising career from the start. That he benefited considerably from his father’s wide-ranging connexions in Northumbrian society is evident from a bequest made to him, in 1410, by the influential landowner, Sir Robert Ogle, who left him two horses and their harness in his will. Thomas was at least 27 years old when his father died, in August 1415, while in office as mayor of Newcastle. He and his mother, Agnes, were made joint executors of his will, under the supervision of Richard Dalton. Although Thomas eventually stood to inherit a considerable amount of land in Alnwick, Ditchburn, Ellington, Earle, Hebburn, Newton-by-the-Sea, Yardhill and Wooler, as well as in Newcastle itself, the allocation of dower properties to his mother (who also retained a life interest in the family home), and the provision of a regular income for his two younger brothers deprived him of almost half his potential income.
So far as we can tell, Thomas sat for Newcastle in only one Parliament, in March 1416, although he did attend the elections of May and December 1421, being named among the 12 probi homines whose task was to choose the parliamentary representatives for the borough. He died young, on 1 July 1422, some two years before his widowed mother, so the Crown was soon able to assert rights of wardship over all the Hebburn estates. Within a few days of his death, John Cerff was granted custody of the lands and marriage of his young son; and it was not until May 1441, when he had already been of age for almost three years that John Hebburn obtained seisin of his inheritance.