After passing through another generation of the Spencer family, in 1669, Althorp made its way into the hands of Robert Spencer, 2nd Earl of Sunderland, who was only an infant at the time.

When he was old enough, Robert started work on the estate, rebuilding the manor and making several changes to the vast property. The grand main house is pictured here in 1677 before renovations took place. You can see the vast empty fields surrounding the house, which are all part of a cultivated estate today.

By the mid-1700s, Althorp was owned by John, 1st Earl Spencer, and his wife, Georgiana Poyntz. It was during John's ownership that Althorp is said to have really come to life.

During the Christmas of 1755, the young John Spencer threw a grand party at the house to celebrate his 21st birthday. According to legend, while the ball was in full swing, he and 18-year-old Georgiana married in secret.

John was apparently taken with Georgiana from the moment he saw her. She clearly felt the same, writing to her friend Thea Cowper: “Since I was born, I never saw anything so charming as he is."

John hosted many parties at Althorp, and the grand estate soon became well-known as a hub for extravagant soirées and festivities.

Georgiana Spencer, the Earl's first daughter, was also born at Althorp in 1757. The great-great-great-great-aunt of Princess Diana, she eventually became the Duchess of Devonshire and a notable English socialite.

She was perhaps most famously portrayed by Keira Knightly in the film The Duchess.

Tour the 90-room home where Princess Diana grew up