Robert Grosvenor, 1st Marquess of Westminster, was the son of the 1st Earl Grosvenor, whom he succeeded in 1802 as 2nd Earl Grosvenor. He was created Marquess of Westminster in 1831. He was an English Member of Parliament (MP) and an ancestor of the modern-day Dukes of Westminster. Grosvenor continued to develop the family's London estates, he rebuilt their country house, Eaton Hall in Cheshire where he also restored the gardens, and built a new London home, Grosvenor House. He maintained and extended the family interests in the acquisition of works of art, and in horse racing and breeding racehorses.

Richard Grosvenor, 1st Earl Grosvenor was an English landowner, Tory politician and peer who sat in the British House of Commons representing the parliamentary constituency of the City of Chester from 1754 to 1761.