The fourth son of Frederick V, Elector of the Palatinate, and his wife Elizabeth, the sister of Charles I, Maurice was born in the castle of Küstrin in Brandenburg shortly after his family was driven from Bohemia during the Thirty Years War. He was named after the Dutch Protestant hero Maurice of Nassau (d.1625). Maurice took up a military career, serving in the Dutch army under the Prince of Orange and in the Swedish army under General Banier. In August 1642, he accompanied his elder brother Prince Rupert to England to fight for their uncle King Charles I against Parliament. While Rupert was given overall command of the Royalist cavalry, Maurice was commissioned colonel of an élite regiment of cavaliers and fought at Powick Bridge, Edgehill and Brentford.
In March 1643, Maurice was given his first independent command when he led an army of 2,000 troops to harass Sir William Waller on the Welsh border. Maurice skirmished and manoeuvred skilfully, winning the battle of Ripple Field in April — the first time that Waller had been defeated. Maurice next commanded the cavalry in the Marquis of Hertford's western army which joined forces with Sir Ralph Hopton's victorious Cornishmen in June 1643. Maurice had wanted command of the entire western army and was resentful towards Hertford. Hopton was dismayed to find that Maurice did little to prevent his unruly cavaliers from plundering civilians in Hopton's home county of Somerset. Despite occasional brawls between the Cornish foot and the Oxford horse, the western army marched against Sir William Waller's headquarters at Bath.
Maurice was wounded and briefly taken prisoner during an attack on Waller's outposts at Chewton Mendip on 12 June 1643. At the battle of Lansdown in July 1643, his cavalry were driven back by Haselrig's Lobsters and many fled the field. Although Lansdown was marginally a Royalist victory, the army suffered severe losses. Hopton himself was badly injured in an ammunition explosion the next day, leaving Maurice to command the withdrawal to Devizes, pursued by Waller's army which had been reinforced from the Bristol garrison. While Hopton and the infantry defended Devizes, Maurice broke out with 300 cavalry and rode to Oxford for reinforcements, covering the 45 miles from Devizes to Oxford in a single night. He returned with Lord Wilmot and Sir John Byron at the head of 1,800 horse which inflicted a grievous defeat on Waller at Roundway Down. Maurice then joined Prince Rupert at the storming of Bristol where he took command of Hopton's Cornish infantry, many of whom were killed in the assault.
After the capture of Bristol, Maurice was given command of the entire western army with orders to reduce remaining Parliamentarian strongholds in the south-west. He marched to consolidate the Earl of Carnarvon's successful campaign in Dorset, where Dorchester, Weymouth and Portland had surrendered on generous terms. However, Maurice did not honour the terms of surrender and once again allowed his men to plunder, prompting Carnarvon to resign his commission in protest and return to Oxford. Maurice then marched to take command at the siege of Exeter, which surrendered on 4 September. The following month, he captured Dartmouth in a surprise attack and seized 40 Parliamentarian ships in the harbour, which made a considerable addition to the Royalist fleet. Maurice next marched to besiege Plymouth but fell sick with fever in mid-November 1643 and withdrew from the siege to recover.
In 1644, Maurice returned to command Royalist forces in the south-west. In April, he became bogged down at the long and costly siege of Lyme in Dorset which he was forced to abandon on 15 June at the approach of the Earl of Essex. Maurice rejoined King Charles and took part in the defeat of Essex at Lostwithiel in September 1644. He was also present at the second battle of Newbury where his cavalry were routed in Waller's flank attack. In 1645, Maurice fought on the Royalist right wing at Naseby with Prince Rupert. He was then appointed governor of Worcester with orders to prepare it as a contingency Royalist capital in case Oxford fell. But when Rupert was disgraced for surrendering Bristol in October 1645, Maurice defended him to the King and accompanied Rupert when he tried to gain a hearing from Charles at Newark. Maurice and Rupert remained loyal to the end. They surrendered at Oxford in June 1646 and were banished from England by order of Parliament.
Maurice returned to the Prince of Orange's army until the summer of 1648 when he joined Prince Rupert and the Prince of Wales (later Charles II) in a squadron of warships that had defected to the Royalists. In 1649, Maurice sailed with Rupert on his raids against Commonwealth shipping from a base at Kinsale in southern Ireland until their squadron was chased by Robert Blake from the Irish Sea to the Mediterranean. When Blake drove the brothers from the Mediterranean, they sailed to West Africa where Maurice raised his flag as Rupert's vice-admiral in a captured English ship, renamed the Defiance. With only four ships remaining, they crossed the Atlantic in 1652 to resume their privateering activities in the West Indies, but Maurice was lost at sea during a storm near the Virgin Islands in mid-September. His loss deeply affected Rupert who for many years believed a persistent rumour that Maurice had survived the storm and was a prisoner of the Spaniards.
References:
Patrick Morrah, Prince Rupert of the Rhine, 1976
G.N. Richardson, Prince Maurice, DNB, 1894
Ian Roy, Maurice, prince palatine of the Rhine, Oxford DNB, 2004