Watson’s great-grandfather, Edward, made a fortune as a diocesan administrator under three bishops of Lincoln. His grandfather, who married into the Northamptonshire Montagu family, bought the manor of Rockingham in 1551, and leased the park and castle from the Crown. The Watsons were notorious for their Catholic sympathies, but James I nevertheless stayed at Rockingham Castle several times.
Looking to re-marry, Watson unsuccessfully courted the daughter of Thomas Watson*, to whom he was apparently unrelated. She rejected him in favour of Sir Robert Sidney*; however, the affair began to generate gossip when ‘not long after this performed contract she was in bed with Sir Lewis’, as Sir John Danvers* wrote to Sir Edward Herbert* on 26 Nov. 1614.
Not long after Watson concluded his purchase of Rockingham, he was informed that both the manor and castle were, in fact, parcel of the duchy of Cornwall, so that he was obliged to obtain statutory confirmation of his rights.
At the next general election Watson initially intended to stand for Northamptonshire. He obtained the support of Sir Francis Fane*, and Montagu, who declared him ‘for his sufficiency and worth every way ... a fit man to serve’; however, the influential Lord Spencer (Sir Robert Spencer†), declared Watson ‘the unfittest of any on that part of the shire’, on the grounds of his religion.
Watson did not stand for election to Charles’s first Parliament. Later in 1625 he supported Montagu in opposing attempts by Fane, now earl of Westmorland, as custos rotulorum, to move the quarter sessions from Northampton to Kettering, an issue that caused bitter factional divisions between the local gentry.
Watson purchased the mastership of the royal buckhounds from Sir Pexall Brocas† in 1634, but three years later he was fined £4,000 for encroachment on the royal forest, and his loyalty waned.
