Thomas Hickman-Windsor, 1st Earl of Plymouth, PC (c.1627 – 3 November 1687) was the son of Dixie Hickman and his wife Elizabeth Windsor, sister and heiress of Thomas, 6th Baron Windsor. He assumed the additional surname of Windsor and succeeded to the Windsor family's estate around Hewell Grange near Redditch in 1645. The same year he distinguished himself in the Battle of Naseby. Hickman-Windsor impressed King Charles I by relieving his garrison at High Ercall.
Upon the Restoration, the title of Baron Windsor, which had last been held by his maternal uncle Thomas, was called out of abeyance in his favour, on 16 June 1660. From 1661 to 1663, he served as Governor of Jamaica.
He acquired the Navigation of the Warwickshire Avon from James, Duke of York and employed Andrew Yarranton to restore Pershore Sluice, thus restoring navigation from Tewkesbury to Evesham. He then sold two-thirds of the navigation above Evesham to Andrew Yarranton and others, who restored the navigation from there to Stratford-upon-Avon. He and George Digby, 2nd Earl of Bristol financed Andrew Yarranton's ultimately unsuccessful attempts to improve the River Salwarpe and River Stour to make them navigable.
He was Gentleman of the Bedchamber to Charles II; in that capacity he was sent in September 1678 with a crucial message to Danby to investigate certain allegations made by Titus Oates and Israel Tonge, thus setting in motion the Popish Plot.
On 6 December 1682, Windsor was created the first Earl of Plymouth, a new creation with the previous title holder having been Charles II's natural son Charles FitzCharles, 1st Earl of Plymouth (1675-1680). He was succeeded by his grandson Other Windsor (his curious first name is a variant of Otho, a remote ancestor).
He married, firstly, Anne Savile, daughter of William Savile, 3rd Baronet, on 12 May 1656. They had three children:
- Lady Mary Windsor (d. 1694)
- Other Windsor, Lord Windsor (1659–1684), father of Other Windsor, 2nd Earl of Plymouth
- Ann Windsor (died in infancy)
On 9 April 1668, he married, secondly, Ursula Widdrington, daughter of Sir Thomas Widdrington. They had six children:
- Dixie Windsor (d. 1743)
- William Windsor (d. 1682)
- Andrews Windsor, to whom his mother gave the Upper Avon Navigation
- Lady Ursula Windsor (d. 1737)
- Lady Elizabeth Windsor (d. 1736)
- Thomas Windsor, 1st Viscount Windsor (d. 1738), to whom his mother gave the Lower Avon Navigation
Re surnames it seems like the Royal Windsors, titled families can make it up as they go along. Thomas was a Hickman by birth not a Windsor yet he gave his children the surname Windsor. Sending the name & title off on a family tangent. The Earl of Plymouths male line from 1905 onwards, goes even further away from the original Baron Windsors who became the Earls of Plymouth (2nd creation) as Robert Windsor-Clive is a Clive by birth.