Peter [the Great] was never again to pursue his dream of opening up a golden road to India, along which would flow unimagined wealth. He had already taken on more than one man could hope to achieve in a lifetime, and accomplished much of it. But long after his death in 1725 a strange and persistent story began to circulate thought Europe about Peter's last will and testament. From his death bed, it was said, he had secretly commanded his heirs and successors to pursue what he believed to be Russia's historical destiny- the domination of the world. Possession of India and Constantinople were the twin keys to this, and he urged them not to rest until both were firmly in Russian hands.

...Catherine [the Great], like Peter, was an expansionist. It was no secret the she dreamed of expelling the Turks from Constantinople and restoring Byzantine rule there, albeit under her firm control.

Peter Hopkirk, The Great Game, p 20-21.