Algernon Capel succeeded his father as second Earl of Essex in 1683 at the age of thirteen. The first earl who had been associated with King Charles II, was disgraced through his involvement with the Rye House plot, which resulted in his imprisonment in the Tower of London and subsequent discovery with his throat cut which was never satisfactorily explained at the time.  The second earl became closely involved with both King William III and Queen Anne, as part of the Whig-supported Protestant Succession.  

In 1692, the Earl married Mary, daughter of Hans Willem Bentinck (King William’s favourite and later first Earl of Portland), having been appointed Gentleman of the Bedchamber immediately on William’s accession in 1688.   The Earl’s career was entirely military and he distinguished himself at the Battle of Landen in 1693. Under Queen Anne, who succeeded in 1702, he was promoted to Major General, and in 1707 he became Lieutenant General of the Queen’s forces.  He was also Lord Lieutenant of Hertfordshire and Constable of the Tower of London.  He died suddenly in the Earl of Portland’s lodgings at Whitehall, London and was buried at Watford on 19th January 1710.  

Contemporary comments stated that he ‘is a good companion; loves the interest of his country; hath no genius for business, nor will ever apply himself that way; is a well bred gentleman; brown complexioned and well shaped, but his mouth is always open’.   He also had the reputation of being ‘the lewdest young man of the town’.   Kneller’s portrait makes strong allusion to the sitter’s military prowess, as he is shown in full armour and distinctive military sash with a battle in progress in the background.

‍