[1] He succeeded to the estates of his father in 1661 and travelled abroad from 1663 to 1666.
In 1669 he was elected Member of Parliament (MP) for Devizes.
He became a freeman of Devizes in 1670 and was Deputy Lieutenant for Glamorgan from 1670 until his death.
[2] Lewis died in London before 23 July 1674, when his will was proved by his brother-in-law William Jephson, who inherited Boarstall, his Buckinghamshire estate.
His younger brother had predeceased him, and the estates in Wales went to his uncle Richard Lewis.