Permira said in a statement that it has agreed to buy R Griggs Group, the owner of the iconic brand of "Doc Martens" boots and shoes, in a deal which ends more than 50 years of family ownership.
The transaction will add Dr. Martens to Permira's brands that include Hugo Boss and Valentino fashion labels, and retail chain New Look.
The Griggs family, who have been making shoes since 1901, will retain around 20 percent of the business after the purchase is completed in January 2014.
"Dr. Martens is an iconic brand with a passionate fan base of followers," said Cheryl Potter, partner and head of the consumer sector team at Permira, in the statement.
"The Permira Funds have extensive expertise in backing global brands, as demonstrated with Hugo Boss and Valentino, and we are looking forward to supporting the management team in this exciting next phase of the company's development."
Dr. Martens began life as a tiny German company making orthopaedic boots, but has since been transformed into a British fashion icon, whose shoes are now worn by trendy artists and world leaders.
The brand dates back to 1959, when two German medics sought to market a shoe with an air-cushion sole, developed by one of them -- Klaus Maertens -- to help him convalesce after a skiing accident.
On April 1, 1960, the first pair of Dr. Martens -- the name was anglicised, for ease of pronunciation -- was produced by the Griggs factory in the village of Wollaston in Northamptonshire, central England.
Dr. Martens was a hit with a series of fashion subcultures, from the skinheads and punks, to the Brit Pop fans of the 1990s.
The brand has enjoyed another revival in recent years, adopted by the likes of pop stars Lady Gaga and Miley Cyrus, actress Emma Watson and model Agyness Deyn.
Tibetan spiritual leader the Dalai Lama is also said to be a fan, as was the late Pope John Paul II.
Production of Dr. Martens boots was mostly moved to Asia in 2002, but the original factory in Woolaston was reopened in 2007 to produce vintage styles.
Dr. Martens currently employs 700 people around the world including 350 staff in Britain, while its products are sold in 63 countries.
More than 100 million pairs of Dr. Martens have been sold since that first pair was produced. There are now around 250 different models, from golden to fuscia, flowered to custom patterned.