John Byron Byron, 1st Baron (c. 1600-1652), English cavalier, was the eldest son of Sir John Byron (d. 1625), a member of an old Lancashire family which had settled at Newstead, near Nottingham. During the third decade of the 17th century Byron was member of parliament for the town and afterwards for the county of Nottingham; and having been knighted and gained some military experience he was an enthusiastic partisan of Charles I. during his struggle with the parliament. In December 1641 the king made him lieutenant of the Tower of London, but in consequence of the persistent demand of the House of Commons he was removed from this position at his own request early in 1642. At the opening of the Civil War Byron joined Charles at York. He was present at the skirmish at Powick Bridge; he commanded his own regiment of horse at Edgehill and at Roundway Down, where he was largely responsible for the royalist victory; and at the first battle of Newbury Falkland placed himself under his orders. In October 1643 he was created Baron Byron of Rochdale, and was soon serving the king in Cheshire, where the soldiers sent over from Ireland augmented his forces.
His defeat at Nantwich, however, in January 1644, compelled him to retire into Chester, and he was made governor of this city by Prince Rupert. At Marston Moor, as previously at Edgehill, Byron's rashness gave a great advantage to the enemy; then after fighting in Lancashire and North Wales he returned to Chester, which he held for about twenty weeks in spite of the king's defeat at Naseby and the general hopelessness of the royal cause. Having obtained favourable terms he surrendered the city in February 1646. Byron took some slight part in the second Civil War, and was one of the seven persons excepted by parliament from all pardon in 1648. But he had already left England, and he lived abroad in attendance on the royal family until his death in Paris in August 1652. Although twice married Byron left no children, and his title descended to his brother Richard (1605-1679), who had been governor of Newark. Byron's five other brothers served Charles I. during the Civil War, and one authority says that the seven Byrons were all present at Edgehill.