Sylvia Stroeher

In 2003, Sylvia Stroeher netted over $1 billion when her family sold 80% of hair-care group Wella AG to Procter & Gamble.

In 1927, her great-grandfather Franz bought the rights to a process that used hot curlers and chemicals to put long-lasting waves into women's hair.

Sylvia and her husband, a former nurse, have a renowned collection of contemporary German art that includes works by Baselitz, Immendorff and Kiefer.

Part of the collection is housed in the Museum Kueppersmuehle in Duisburg, Germany.

An extension to the museum by star architect Pierre de Meuron opened in 2020.