Cownden’s will suggests that he was descended from a modest gentry family originally from Durham but resident in the East Riding of Yorkshire by the early seventeenth century.
Cownden was elected for Southwark in 1604. According to a document among the papers of Sir George More*, he was among those added to the committee to consider the bill to reform the Marshalsea, which was situated in Southwark, on 21 Mar. 1606, but he does not appear in the list in the Journal, and left no further mark on the records of the first Jacobean Parliament.
He made his will on 2 Jan. 1610. His charitable bequests included £5 to the poor of his parish, £50 towards the purchase of the fee-farm of the parsonage, and £5 to the vestrymen for a dinner. He gave £2 for a funeral sermon to William Symons, preacher at St. Saviour’s and, according to Wood, ‘of rare understanding in prophetical scriptures’. His property consisted chiefly of tenements in Southwark and Newington, but included a more substantial messuage called The Three Falcons. Under his will his widow, who had brought him a third share in the Lilypot in Billingsgate, was to have the £800 settled on her at marriage and their dwelling-house, as well as such possessions as her own plate, a beer-bowl, a wine-bowl, a silver beaker, ‘one fair round gilt salt of silver and also the fairest and largest tapestry coverlet’. His executors included John Bingham, who was later to marry his widow, her brother-in-law Edward Bromfield, whose elder brother was to represent Southwark in 1621 and 1624, and his friends John Marshall and William Mayhew*. Cownden died four days later and was buried in St. Saviour’s church, in accordance with his request, on the same day. His only son John, who married Mayhew’s daughter-in-law, died without issue in 1613, and no other member of the family entered Parliament.