Prince Philip sacrificed an important part of his life for Queen Elizabeth before tying the knot

Prince Philip had to accept a major condition put forth by Queen Elizabeth before the two married each other. 

The monarch was strict about one major thing in the Duke's life, which was his perpetual smoking, and made him give it up before agreeing to exchange vows.

This was because the young ruler had lost her father, King George VI, to cancer as he was a heavy smoker.

The disease had caused his untimely death in 1952 at just 56.

The rule laid down for Prince Philip by his wife is detailed by royal author Bryan Kozlowski in his new book Long Live the Queen! 13 Rules for Living from Britain's Longest Reigning Monarch, wherein he writes how Elizabeth insisted that Philip kick the habit when they married in 1947.

The King consort actually did give his smoking up, but not until the actual day of their wedding.

"Understandably, Elizabeth was adamant that Philip give up the habit that wreaked her father's health," Kozlowski pens.

"Previously a heavy smoker himself, Philip obliged with phenomenal efficiency, going from a pack a day to quitting cold turkey on his wedding day," he adds.