Over the last century, the Orthodox Christian population around the world has more than doubled and now stands at nearly 260 million. In Russia alone, it has surpassed 100 million, a sharp resurgence after the fall of the Soviet Union. Yet despite these increases in absolute numbers, Orthodox Christians have been declining as a share of the overall Christian population -- and the global population -- due to far faster growth among Protestants, Catholics and non-Christians. Today, just 12% of Christians around the world are Orthodox, compared with an estimated 20% a century ago. And 4% of the total global population is Orthodox, compared with an estimated 7% in 1910.