In his youth Halswell enjoyed an extended education, which included a period of travel on the Continent with his Somerset neighbour, Sir Robert Phelips*. He arrived back in London in time to witness the first parliamentary session of 1610, in which his father was sitting for Bridgwater, and on 19 Apr. he dined with his kinsman Sir Richard Paulet*. Together with the latter, he heard a preacher at St. Paul’s Cathedral on 10 June, and then ‘went with my Lord and Lady Saye to a sermon in a church near Leadenhall’.
After his marriage, Halswell continued to live at his ancestral home in Goathurst, where his three children were born. In 1614 he succeeded his father, Sir Nicholas, as a Member for Bridgwater, doubtless securing his seat on the strength of his family’s property in and around the town, and his father’s prominence in local politics. He left no trace on the records of this Parliament, and seems not to have communicated with his constituency in the way that Sir Nicholas had formerly done.
Halswell never returned to the Commons, his prospects by the following decade blighted by his father’s mounting financial difficulties, which necessitated the sale or mortgage of many of the family’s lands. In 1620 he was party to a £750 loan taken out by Sir Nicholas, which was secured on an annuity out of one of his estates.
