He was educated at Eton 1776-1783 and matriculated at Oxford, 14 January 1784. During his father's lifetime, as Marquess of Blandford, he lived at White Knights near Reading, employing 23 men to keep his remarkable gardens in order. These became legendary but, sadly during his lifetime, most of his art collection as well as his library had to be sold.
These were not his only problems in life. A Mrs. Gunning decided not only that her daughter, Gunnilda, should become a Duchess but that the Marquess of Blandford should be the one to make this possible. Forging love letters supposedly written by Blandford to Gunnilda, Mrs.Gunning gave them to her husband, General Gunning. Unaware of the forgery, the General approached Blandford's parents. The latter did not object to the marriage but, when Blandford denied any knowledge of the letters, their forgery was exposed. General Gunning then turned his wife and daughter out of his house while Blandford hastily married Lady Susan Stewart.
George was an M.P. for Oxon, 1790-1796, and for Tregony, 1802-1804; a Lord of the Treasury, 1804-1806. He was a defendant in an action for criminal connection, 27 May 1801, with Lady Mary Anne Sturt, wife of Charles Sturt, who laid the damages at 20,000 pounds but obtained only
a hundred pounds. By Royal licence, 26 May 1817, he took the name of Churchill after that of Spencer. Earlier the same year he became Duke of Marlborough. Due to his previous extravagance, he was forced to sell many of the treasures of Blenheim and to close many of the rooms.
Consequently, his wife left him as so did his mistress, Lady Mary Ann Sturt. When he died, he left as much as he could to a Matilda Glover.
 

Source: Leo van de Pas