Russian Orthodox leader warns Turkey over Hagia Sophia move
Hagia Sophia is the former Greek Orthodox Christian patriarchal cathedral, later an Ottoman imperial mosque and now a museum.
What you need to know:
Turkey's top court is debating whether one of the architectural wonders of the world can be redesignated as a mosque, a move that could inflame tensions with the West and the Christian community.
"A threat to Hagia Sophia is a threat to the whole of Christian civilisation, and therefore to our spirituality and history," the Orthodox church leader said.
