He was the son of Robert Rich, 1st Earl of Warwick and of Penelope Devereux, Lady Rich, and the younger brother of Robert Rich, 2nd Earl of Warwick. He began his career as a courtier and soldier in 1610, swiftly becoming a favourite of King James I of England, but fell out of favour on the accession of Charles I. He was created Baron Kensington in 1622, and Earl of Holland in 1624. He was the lover of Marie de Rohan. On Sunday, 9 July 1648, seven months prior to the execution of King Charles, the Earl and his army of approximately 400 men entered St Neots in the county of Huntingdonshire. The Earl's men were hungry and weary, following their escape from Kingston upon Thames, where the Parliamentary forces had completely overwhelmed them. Of his original army of 500, the Earl escaped with around 100 horsemen and were immediately followed by a small party of Puritan and Parliamentary horsemen. After much hesitation regarding in which direction they should flee, the Earl decided on Northampton, and the group made their way via St Albans and Dunstable. Upon the outskirts of Bedford the group turned eastward towards St Neots town. En route from Kingston, the Earl was joined by the young Duke of Buckingham and the Earl of Peterborough. Colonel John Dalbier, an experienced German soldier, had also joined them. The Roundheads hated Dalbier, as he had previously served with them under the 3rd Earl of Essex until taking up arms in favour of the Cavaliers cause. The field officers of Holland’s force sought only rest and safety. Colonel Dalbier called a council of war, where many officers voted for dispersing into the surrounding countryside. Others suggested they should continue northwards. Colonel Dalbier advised on the strategic position of St Neots and the fact that the joint remnants of Buckingham and Holland’s forces had increased sufficiently since the retreat from the Roundheads at Kingston. He suggested they meet and engage their pursuers. He further added that, by obtaining a victory, the fortunes of war could be turned in their favour. Due to his vast experience as a soldier, his words were listened to with respect. He further offered to guard them through the night in case of a surprise attack, or meet the death of a soldier in the defence of the town. A vote was taken and Dalbier’s plan was adopted. The Earl of Holland who, it was said, "had better faculty at public address than he had with a sword," joined the Duke of Buckingham and the Earl of Peterborough in addressing the principal residents and townsfolk of St Neots. Buckingham spoke at length, claiming "they did not wish to continue a bloody war, but wanted only a settled government under Royal King Charles." Assurances were also given that their Royalist troop would not riot or damage the townfolks’ property. Of the latter, it is recorded that they were faithful to their promise. Fatigued by their battle and consequent retreat from Kingston, the field officers eagerly sought rest. Colonel Dalbier, true to his word, kept watch over them. The small group of Puritan horsemen who had pursued them had, upon reaching Hertford, met with Colonel Scroope and his Roundhead troops from their detachment at Colchester. At 2 o’clock on Monday morning, 10 July, one hundred Dragoons from the Parliament forces arrived ahead of the main army at Eaton Ford. Colonel Dalbier was at once informed, and immediately gave the alarm: "To horse, to horse!" The Dragoons, equipped with musket and sword, crossed St Neots’ bridge before the Royalists were fully prepared. The Battle of St Neots had begun. The few Royalists guarding the bridge quickly fell back from the superior numbers before them. The ensuing battle was now fought on the main square and streets of the town. The remaining Royalists were now fully prepared for combat. The main army of Roundheads had also arrived, and a further wave of Puritans crossed the bridge into town. The battle was fierce, with the Puritans gaining ground. Colonel Dalbier died during the early stages of the battle. Other prominent Royalists, including Buckingham's younger brother Francis Villiers, and Kenelm Digby (son of the scientific writer of the same name), were also killed during the battle. Other officers and men drowned whilst attempting to escape by crossing the River Ouse. The young Duke of Buckingham, being overwhelmed by the speed of these events, escaped to Huntingdon with sixty horsemen, with the intention of continuing towards Lincolnshire. Upon realising the Roundheads were in hot pursuit, he changed plans, and via an evasive route returned to London from where he later escaped to France. The Earl of Holland with his personal guard fought their way to the inn at which he had stayed the previous night. The gates had been closed and locked, but were quickly opened to admit him, and immediately closed again as he entered. The Parliamentarians soon battered them down and entered the inn. The door of the Earl’s room was burst open to reveal him facing them, sword in hand. It is recorded that he offered surrender of himself, his army and the town of St Neots, on condition that his life was spared. The Puritans seized the Earl and took him before Colonel Scroope, who ordered him to be shackled and imprisoned under guard. The remaining Royalist prisoners were locked in St Neots parish church overnight, then taken to Hitchin the following morning. The Earl and five other field officers were taken to Warwick Castle, which had remained a parliamentary stronghold throughout the war. They remained prisoners for the next six months, until their trial for high treason. In London it was said "His Lordship may spend time as well as he can and have leisure to repent his juvenile folly." The Earl of Peterborough also escaped dressed as a gentleman merchant, but was later recognised and arrested. Friends aided their escape again whilst en route to London for trial. He then stayed at various safe houses, financed by his mother, until he managed to flee the country. On 27 February 1649, the Earl of Holland was moved to London for trial. He pleaded his crime was not capital, and claimed that he had surrendered St Neots town on the condition that his life would be spared. It was stated at the time that in 1643 Earl of Holland had joined Parliament and in the same year had changed sides and joined the Royalists. He was with them at the Battle of Chalgrove – Oxford – but stole away during a dark night before the close of battle. On 3 March the Earl was condemned as a traitor and was sentenced to death. His brother, the Earl of Warwick, and the Countess of Warwick petitioned Parliament for his life, as did other ladies of rank. The Puritan Parliament divided its vote equally. The speaker gave the casting vote for the sentence to stand. The petition had succeeded only in deferring the execution for two days. The Earl was dangerously ill during these days and neither ate nor slept.

His executionOn the morning of his execution, 9 March, before Westminster Hall, the Earl walked unaided, but spoke to people along the way, declaring his surrender at St Neots was on condition that his life would be spared. At the scaffold he prayed. He then gave his forgiveness to the executioner and gave him what money he still had on his person, which was approximately ten pounds. Upon laying his head on the block, he signalled the executioner by stretching his arms outwards. His head was severed by one stroke of the executioner’s axe. Very little blood flowed, due to his weakness, and the strong feeling was that, even had the execution not taken place, he probably would not have lived for long. The second rising of the English Civil War had culminated in the Battle of Preston during August 1648, with the Roundheads marching two hundred and fifty miles in twenty six days through foul weather and conditions, to defeat and ensure the Royalists would never re-form as an army. The townspeople of St Neots, who apparently were neutral during the entire conflict, continued their peaceful existence.