Decades of assassinating political enemies, repressing his people, rigging his country's elections and invading other nations appear have caught up to Vladimir Putin.

For all his macho posturing, whether it be riding a horse shirtless, taking judo lessons or even tranquillising tigers and polar bears, Putin is said to be petrified of mortality.

The tyrant is said to have spent much of his precious time investigating ways to prolong his life.

Yesterday, we saw a rare glimpse into this fear of death, having been caught rambling about immortality during a summit with Xi Jinping and Kim Jong Un.

Putin, who is in Beijing with the North Korean ruler and dozens of other world leaders to celebrate the 80th anniversary of the end of World War II, was caught in a rare candid conversation with China's premier.