After the transfer of Athos to the Kingdom of Greece in 1912, and especially with the start of World War I in 1914, the stream of pilgrims and monks from Russia was disrupted and later was strictly controlled by the government of Greece until the collapse of the USSR in 1991. As a result, the number of Russian monks in the monastery and on Mount Athos generally, was reduced from several thousand in the 1900s to 13 in the early 1970s.