William Cavendish, the son of Sir Charles Cavendish and Catherine Ogle and a descendant of the famous Cavendish family, was born on December 6, 1592 at Hardsworth Manor in Yorkshire. Shortly after William's birth, his brother Charles was born. In part because of their close proximity in age, William and Charles would maintain a close relationship throughout their lives. William Cavendish, an English polymath and aristocrat, had also previously been a poet, equestrian, playwright, politician, swordsman, diplomat, solider and, last but not least, architect.
Cavendish was the eldest surviving son of Sir Charles Cavendish and his wife, Catherine, and the grandson of Sir William Cavendish and Bess of Hardwick. William was made a Knight of the Bath in 1610, and, after his travels with Sir Henry Wotton, he was made ambassador to the Duke of Savoy. He married his first wife, Elizabeth, upon his return to Welbeck Abbey. As he was quite wealthy, Cavendish entertained King James I and King Charles I with great magnificence at both Welbeck and Bolsover.
William Cavendish became Viscount Mansfield on November 3, 1620, and, on March 7, 1628, he became Earl of Newcastle-upon-Tyne. He then inherited his mother's barony of Ogle after she passed away in 1629, along with her entire estate worth 3,000 pounds annually. He assisted King Charles with a loan and a troop of volunteer horses, which contained 120 knights and gentlemen, when the Scottish war broke out from 1639-1640.
In 1641, William Cavendish, Earl of Newcastle-upon-Tyne became involved in the English Civil War with King Charles and, once Charles declared open war, Cavendish was charged with commanding the four northern counties. He was also vested with the power to make men knights. William maintained the troops under his command at his own expense and dispatched his foreign supplies to the king. Cavendish was made Marquess of Newcastle-upon-Tyne in October 1643, shortly before the English Civil War ended in disaster.
After the disaster that was the English Civil War, William Cavendish announced his intention to leave England, and was accompanied by quite a following, which included, among many others, his brother and two sons. He lived at Hamburg from July 1644 to February 1645, before moving to Paris, where he lived for three years. While living in Paris, he met and married his second wife, Margaret, a dramatist and romancer, who later wrote a biography on her husband, who was 25 years her senior. William Cavendish expressed his love and admiration for his wife in a sonnet he wrote as an introduction to her masterpiece, The Blazing World.
Cavendish left Paris and moved to Rotterdam in 1628. Despite his intention of joining the Prince of Wales in commanding the rebellious navy, he decided instead to take up residence at Antwerp where he lived until the Restoration. In Anterwerp, he lived in the Rubenshuis, where he established his horse riding school and published his first work on horsemanship titled A General System of Horsemanship. After the Restoration, he returned to England, where he succeeded in regaining the greater part of his estates, although he suffered losses in the war of 941,303 pounds. In March 1665, William Cavendish was made a duke.
With John Dryden's assistance, in 1688 William Cavendish translated Moliere's L'Etourdi as Sir Martin Mar-All. He also contributed scenes to his wife's plays and his poems are also found throughout many of her works. Cavendish never fully recovered from Margaret's sudden death. During his later years, William Cavendish suffered from Parkinson's disease and died at Welbeck Abbey on Christmas Day 1676. He was buried in Westminster Abbey.