Christopher was born at Pavlovsk, Imperial Russia, son of King George I of Greece and Queen Olga, a Russian grand duchess by birth.

While a young man, he was apparently offered no fewer than three different thrones - those of Portugal,[5] Lithuania, and Albania - but he declined them all, as he did not wish the stress of royal duties.

On 1 January 1920, Christopher married a very wealthy American widow, Nonnie May "Nancy" Stewart Worthington Leeds, at Vevey, Switzerland.

[1][2][6] His bride, a once-divorced and once-widowed commoner at least a decade older than the prince, was nonetheless recognised as Christopher's dynastic wife by his family[2] (at the time of the engagement and wedding, the Greek royal family lived frugally in exile, and as Christopher was last in the dynasty's order of succession, any children he fathered would not impact the succession rights of other Greek dynasts).

Her fortune, estimated in the tens of millions of dollars, was inherited from her second husband, a tin millionaire,[1] and substantially eased the Greek royal family's exile during the 1920s.

"[7] Prince Christopher described her: "In the first place she was unable to speak Russian, which the Grand Duchess Anastasia, like all the Czar's children, had talked fluently − and would only converse in German.

"[7] Summing up, he said of her, "The poor girl was a pathetic figure in her loneliness and ill health, and it was comprehensible enough that many of those around her let their sympathy over-rule their logic.... She was unable to recognise people who the Grand Duchess Anastasia had known intimately, and her descriptions of rooms in the different palaces and of other scenes familiar to any of the Imperial Family were often inaccurate.