Semahat Sevim Arsel

Sits on the board of her family's conglomerate, Koc Group, but has no role in management. Spent years battling an illness in hospitals around the world; the experience moved her to build nursing education and research center in Turkey. Married a doctor. Fluent in English and German. Brother Rahmi Koc, sister Suna Kirac and nephws Mustafa, Omer and Ali Koc are also billionaires.