Mayor of London Boris Johnson visited the Old Kent Road Mosque on Friday.
The Mayor was accompanied by his deputy, Sir Edward Lister.
The Mayor gave a speech extolling the virtues of London as a multicultural city and argued that the London 2012 Olympic and Paralympic games had shown the capital at its best.
"This mosque is an example of the kind of institution that helped to create that effect in the summer of 2012," said Mr Johnson.
In his speech the Mayor drew on his own background as the descendent of an immigrant from Turkey.
He said: "You may not believe this, but my great grandfather came to London – and he was a Muslim. He knew the Koran off by heart in Arabic.
"I think he would have been absolutely astonished to find that his great grandson had become Mayor of London...
"I end on that point because it shows that this is a city that can welcome anybody from any background and they can achieve whatever they want in their life."