BREMEN: Germany's president called on his countrymen to work to integrate the country's four million Muslims, acknowledging that Islam is “now part of Germany”. Speaking from the northern city of Bremen on the 20th anniversary of reunification and in his first major set-piece speech, Christian Wulff focussed on the challenges ahead of modern, reunited Germany. In particular, he spoke of the difficulties of integrating its large Muslim population. “Twenty years after reunification, we stand before the huge task of finding new solidarity in a Germany that is part of a swiftly changing world,” he said. “Christianity is of course part of Germany. Judaism is of course part of Germany. This is our Judeo-Christian history ... But now Islam is also part of Germany,” he added. “When German Muslims write to me to say ‘you are our president', I reply with all my heart ‘yes, of course I am your president'.” Germany has four million Muslims among its 82 million inhabitants and the issue of their integration has been in the headlines for months. A member of Germany's central bank, Thilo Sarrazin, sparked outrage when he said the country was being made “more stupid” by poorly educated and unproductive Muslim immigrants and soon after was forced to resign. Wulff called for more tolerance from ordinary Germans, but he also insisted that immigrants make a real effort to integrate. Those living in Germany should adhere to the country's constitution and its way of life, including learning the language, he said. Wulff hailed the reunification of the free-market West and communist East barely a year after the Berlin Wall fell as “a momentous day that a people experience only rarely”. “I bow before everyone who fought for freedom ... your courage moved the world,” he told an audience of dignitaries including Chancellor Angela Merkel and European Union President Herman Van Rompuy, to generous applause.