Question: Which English military leader was the father of  Elizabeth Capell, Countess of Essex

Context paragraphs:
Algernon Percy, 10th Earl of Northumberland: Algernon Percy, 10th Earl of Northumberland, 4th Baron Percy, KG (29 September 1602 – 13 October 1668) was an English military leader and a prominent supporter of the Parliamentary cause in the English Civil War.

Edward Whalley: Edward Whalley (c. 1607 – c. 1675) was an English military leader during the English Civil War, and was one of the regicides who signed the death warrant of King Charles I of England.

Horace Vere, 1st Baron Vere of Tilbury: Horace Vere, 1st Baron Vere of Tilbury (1565 – 2 May 1635) (also "Horatio Vere" or "Horatio de Vere") was an English military leader during the Eighty Years' War and the Thirty Years' War, a son of Geoffrey Vere and brother of Francis Vere.  He was sent to the Palatinate by James I in 1620.  He was created Baron Vere of Tilbury, and died without a male heir.

Talbot Shrewsbury Book: The Talbot Shrewsbury Book (London, British Library Royal 15 E vi) is a very large richly-illuminated manuscript made in Rouen (Normandy) in 1444/5.  It was presented by John Talbot, 1st Earl of Shrewsbury (d. 1453) to the French princess, Margaret of Anjou (b. 1430, d. 1482), in honour of her betrothal to King Henry VI (r. 1422-1461).  It contains a unique collection of fifteen texts in French, including chansons de geste, chivalric romances, treatises on warfare and chivalry, and finally the Statues of the Order of the Garter.  The work is an excellent example of book production in Rouen in the mid-fifteenth century and provides a rare insight into the political views of the English military leader and close confidant of the crown, John Talbot.

Baron Russell of Thornhaugh: Baron Russell of Thornhaugh is a title in the Peerage of England.  It was created in 1603 for the English military leader, the Honourable Sir William Russell.  He was the fourth son of Francis Russell, 2nd Earl of Bedford.  His son succeeded as Earl of Bedford in 1627 and the barony has been united with the earldom ever since.

Charles Howard, 1st Earl of Carlisle: Charles Howard, 1st Earl of Carlisle (1629 – 24 February 1685) was an English military leader and politician who sat in the House of Commons at various times between 1653 and 1660 and was created Earl of Carlisle in 1661.

Paul Capell, 11th Earl of Essex: Frederick Paul de Vere Capell, 11th Earl of Essex (born 29 May 1944) is the current Earl of Essex.  He succeeded his father Robert Capell, 10th Earl of Essex, in 2005.

Andrew Harclay, 1st Earl of Carlisle: Andrew Harclay, 1st Earl of Carlisle (ca. 1270 – 3 March 1323), alternatively Andreas de Harcla, was an important English military leader in the borderlands with Scotland during the reign of Edward II.  Coming from a knightly family in Westmorland, he was appointed sheriff of Cumberland in 1311.  He distinguished himself in the Scottish Wars, and in 1315 repulsed a siege on Carlisle Castle by Robert the Bruce.  Shortly after this, he was taken captive by the Scots, and only released after a substantial ransom had been paid.  His greatest achievement came in 1322, when he defeated the rebellious baron Thomas of Lancaster at the Battle of Boroughbridge on 16–17 March.  For this he was created Earl of Carlisle.

Elizabeth Capell, Countess of Essex: Elizabeth Capell, Countess of Essex (1 December 1636 – 5 February 1718; née Percy) was an English noblewoman, the daughter of Algernon Percy, 10th Earl of Northumberland.  She was the wife of Arthur Capell, 1st Earl of Essex.  Elizabeth was the subject of a portrait by court painter Sir Peter Lely.

Adele Capell, Countess of Essex: Adele Capell, Countess of Essex (née Adele Grant) was a US-born socialite who married into the British nobility.

Supporting paragraphs: Elizabeth Capell, Countess of Essex Algernon Percy, 10th Earl of Northumberland
Answer: Algernon Percy