Philosopher and politician Ralf Dahrendorf, who claimed class was defined by power not wealth, has died of cancer, aged 80.

Prof. Dahrendorf, born in the German city of Hamburg, took British citizenship in 1988, and served as a politician in both countries and as a European Commissioner.

"Europe has lost one of its most important thinkers and intellectuals," Germany's Chancellor Angela Merkel said in Brussels yesterday while attending a European Union summit.

"We've lost a great European. He made great contributions to European integration from both a theoretical and practical point of view."