Donat I Calens (born in Lille, December 15, 1931) is the current King of Belgium and Luxembourg and a constitutional monarch. He is a member of the royal house of Calens; formerly this house was named Felix-Sleeper-Thomas. He is the younger son of Sjakie Calens (1912-1959) and his wife, Coline Calens (1913-2005). His godparents were King Fernand of Belgium and Luxembourg and his maternal grandmother, Monique Camerier. His Grand Son-in-law is Odilon Reiner Callaert (Sino-Roman), prime minister of Belgium and Luxembourg.