The Happy Valley set was a group of hedonistic, mostly British and Anglo-Irish aristocrats and adventurers who settled in the 'Happy Valley' region in colonial Kenya between the 1920s and the 1940s. By the 1930s, the group became infamous for its decadent lifestyles and debauchery.

Hugh Cholmondeley, 3rd Baron Delamere (1870–1931), is credited with helping form the Happy Valley set. Lord Delamere first went to Africa in 1891 for hunting and returned yearly until he was mauled by a lion. As a result, he limped for the rest of his life.

In 1906, he became the leader of the white community in Kenya. At the outbreak of WWI, Delamere was placed in charge of intelligence on the Maasai border, monitoring the movements of German units in present-day Tanzania.

The area was one of the first to be settled in Kenya by white people. Some of the notable members of the Happy Valley set were, The 3rd Baron Delamere, his son and heir, The 4th Baron Delamere, Denys Finch Hatton, Sir Jock Delves Broughton and Diana Delves Broughton, The 22nd Earl of Erroll, Lady Idina Sackville, Alice, Countess de Janze and Count Frederic de Janzé.

"Witty, attractive, well-bred, and well-read, Happy Valleyites were relentless in their pursuit to be amused, more often attaining this through drink, drugs & sex." There was heavy morphine, heroine, and cocaine use and lots of sexual promiscuity. A scandalous murder, recession & Wall Street stock market crash eventually decreased the size of the group.

More Info: en.wikipedia.org