The younger brother of the 2nd Earl of Warwick, Henry Rich was an adroit courtier and became a favourite of King James I, the 1st Duke of Buckingham and King Charles I. During King James' reign he was created Baron Kensington, then Earl of Holland in 1624. In the 1630s he became a favourite of Queen Henrietta Maria, who used her influence to have him appointed Groom of the Stole in 1636 and even to replace the Earl of Essex as Lieutenant-General of Horse in the First Bishops' War of 1639. Holland's cavalry retreated from the Scots at Kelso, leading to a collapse of morale in the English army and the beginning of negotiations between the King and the Covenanters.
Holland declined to join the King when he issued his call-to-arms at York in 1642 but remained in London, where he was appointed to Parliament's Committee of Safety. He became one of the "Peace Party" in Parliament attempting to secure a negotiated settlement with the King. In August 1643, however, he left London to join the King at Oxford. He resumed his military career fighting for the King and distinguished himself at the siege of Gloucester and the first battle of Newbury. The Queen was now hostile towards him and frustrated his ambitions for high office at court. Holland returned to London in 1644, but found himself barred from the House of Lords. He continued to seek a compromise settlement, and in 1645 was active in negotiations for a separate peace treaty between King Charles, the Scottish Covenanters and the English Presbyterians.
In July 1648, during the Second Civil War, Holland accompanied the 2nd Duke of Buckingham and Buckingham's brother, Lord Francis Villiers, in leading a Royalist insurrection at Kingston in Surrey. Within a week of declaring for the King, Lord Francis had been killed, Buckingham had fled abroad and Holland was a prisoner. Along with other Royalist leaders, he was brought to trial and condemned to death for inciting a second civil war. His brother the Earl of Warwick and Lord-General Fairfax both interceded on his behalf but Parliament upheld the death sentence by 31 votes to 30. The news of the vote brought about a profound spiritual conversion in Holland just before his execution at Westminster on 9 March 1649.
References:
R. Malcolm Smuts, Henry Rich, first earl of Holland, Oxford DNB, 2004