Interestingly, however, Prince Charles' current wife, Camilla, Duchess of Cornwall, is a Cancer, the same sun sign as the late Crown Princess.

"Prince Charles married two women in his lifetime, both of whom were Cancer. Cancer is known as a sign that loves family life, stability, and peace," astrologer Inbaal Honigmann told the Express. [Cancerians tend to enjoy a quiet life, surrounded by close friends and relatives. Their joy comes not from achievement or accomplishment, but from just living and loving."

"Cancerians are not afraid to be alone.

So what differences are there in the three birth charts that mean that Prince Charles' second marriage is much more tranquil than his first?

"As a young Scorpio, the Prince embodied the impulsive element of the sign of Scorpio, and while he may have chosen to react rather than listen in his first marriage, he was more mature in his second," Honigmann continued.

"The older Scorpio will mellow a lot and feel more in tune with the receptive and nonjudgmental elements of this sign, and will carry this into later marriages."

As one possible reason why Princess Diana was not compatible with Prince Charles (Ascendant in Leo), Honigmann says, "Diana's Ascendant in Sagittarius would have turned her toward personal freedom, creativity, and expression. These two astrological placements do not easily coincide."