Former German president Johannes Rau has died at his home at the age of 75 after a long illness. Rau, a Social Democrat, was head of the North Rhine- Westphalia region between 1978 and 1998. He then served one term as German president before being replaced by Horst Koehler in 2004. He was the third of five children born into a staunchly religious family.As a schoolboy he was active in the Confessing Church, a circle of the German Protestant Church, which actively resisted the Nazis. He was also a member of the All-German People’s Party which called for German Reunification and was disbanded in 1957. Rau and his political mentor Gustav Heinemann joined the Social Democratic Party in 1958. The same year, he was elected for the first time as member of the parliament of North Rhine Westphalia, before becoming head of the state in 1978, where he remained for 20 years with four successful elections. He is survived by his wife and three children.