The Red Crescent emblem was first used by ICRC volunteers during the armed conflict of 1876–1878 between the Ottoman Empire and the Russian Empire. The symbol was officially adopted in 1929, and so far 33 states in the Muslim world have recognized it. In common with the official promotion of the red cross symbol as a colour-reversal of the Swiss flag (rather than a religious symbol), the red crescent is similarly presented as being derived from a colour-reversal of the flag of the Ottoman Empire.