His grandfather was the Royalist hero Sir Bevil Grenville (1596–1643) who died at the Battle of Lansdowne, while his father was Groom of the Chamber to Charles II and MP for various constituencies from 1661 to 1698.

In June 1685, he was commissioned as captain in a regiment raised by his uncle, the Earl of Bath, part of an expansion of the military by James II following the Monmouth Rebellion.

[a] During the Siege of Namur in June 1695, he fought a duel with the Marquis de Rade, a French Huguenot exile and Colonel of the 6th Foot, who died of wounds shortly afterwards.

[5] His regiment returned to England in early 1696 due to fears of a Jacobite invasion, and in a demonstration of his perceived reliability, on 21 March he was appointed Governor of Pendennis Castle in Cornwall.

[11] Although "honourably acquitted" at a hearing on 20 July 1705, Granville asked Marlborough to approve his recall, which he did;[c] on 15 September 1706, he died of fever on board the ship bringing him home.