He spent the rest of the war in the West Country; arrested for insubordination by Sir Ralph Hopton in early 1646, he was released when the Royalists surrendered in March.

His colleagues included future Civil War generals Sir Ralph Hopton and William Waller; it appears likely all three were members of the English garrison of Frankenthal, which surrendered to the Catholic League in March 1623.

[6] He escaped in 1633, and fled to the Dutch Republic, where he studied mathematics at Leiden University, a subject popular with professional soldiers, due to its applications in siege warfare.

[3] In February 1642, Grenville was part of the army sent to suppress the Irish Rebellion, where he gained a reputation as a competent, but ruthless leader, and was appointed governor of Trim, County Meath.

In June 1643, the rebels agreed a truce with Ormond, leader of the Irish Royalists, formally confirmed in September when both sides signed a Cessation of Arms.

One suggestion is the death of his elder brother at Lansdowne in July provided an opportunity to assume leadership of the Royalist movement in Cornwall, which was intensely local.

[8] In return for swearing loyalty, Grenville received his wages and was appointed Lieutenant-General of Horse in the Army of the South Eastern Association, led by his former colleague, William Waller.

[10] As the war turned against the Royalists, internal conflict increased; Grenville refused orders from Prince Rupert to support an attack on Taunton, then quarrelled with Lord Goring, commander of the Western Army.

[11] By the end of 1645, the Royalists in the West Country were close to defeat, and Grenville proposed setting up an autonomous Cornwall, under the Prince of Wales, and negotiating a truce with Parliament.

When Hopton replaced Goring as commander in the West, Grenville refused to serve under him; in January 1646, he was arrested for insubordination and imprisoned on St Michael's Mount.

In 1654, he published his Single defence against all aspersions of all malignant persons, giving his version of events in the West; in 1736, it appeared in the Works of George Grenville, Lord Lansdowne.

[16] The author Daphne du Maurier's novel The King's General (April 1946) tells the story of Sir Richard Grenville's life and exile, introducing fictional characters but based strongly on historical facts.