St. James Square was already beginning to pall as a fashionable area by the time of the Regency. Yet the simple, classically styled No. 10 survived to become, by virtue of its occupants alone, a salon rivalling any in Kensington and Berkely Square.
No. 10 was purchased by Sir William Heathcoate, a merchant elevated to the peerage. He married the only daughter of his neighbor in no. 11, the Earl of Macclesfield and one-time Regent of Great Britain. His family owned the house until 1890.
During that period, the house was leased to a variety of renters, the first being William Pitt the Elder. When he was Secretary of State, he conducted government business in the house and one time from his bed when he was ill. The Prime Minister at the time was the Duke of Newcastle. He had gone to No. 10 to transact some business with Pitt. The two did not get along. Maybe that was why His Grace complained of the cold in Pitt’s bedroom. When no sympathy was forthcoming, he cursed and climbed into the other bed in the room to finish his business with the Secretary.
Mr. Pitt moved out of the cold house in 1762 and No. 10 saw a number of tenants until it began service as a gaming hell. Then it became known as a snug little place, “a low house, humorously called a pigeon hole.” With expenses kept to a minimum, no. 10 was rumored to bring in 30,000 pounds in 1817.
Then in 1820, the house was let by one Charles John Gardiner, Earl of Blessington. He had a new countess, and the house was ordered fitted up to her high expectations.
Society thought her bohemian before they knew where Bohemia was.