Reaching majority by 1552, he was party to a legal dispute over lands he bought in Lincolnshire, being described as “William Tyrwhitt esquire, a young gentleman, son and heir apparent of Sir Robert Tyrwhitt of Lincolnshire, a man of great power in those parts”. In 1553 he was selected as MP for the borough of Huntingdon, his father being in the same Parliament for the seat of
Lincolnshire. made two months earlier, asked for his body to be buried beside his father in All Saints church at
Bigby and for lands to be sold, including the manor of
Fillingham, in order to provide legacies for his children. ==Family==