When it comes to the British royal family, titles are both important and tricky. This is partially due to the fact that there is so much tradition surrounding the order of how they are assigned.

The monarchs of the family, known as the king or queen, are two of the most well-known roles. However, some members of the family, such as Prince Philip, cannot receive the title of king even though he is married to Queen Elizabeth II. In contrast, Camilla, Duchess of Cornwall could become queen as Prince Charles' wife. Why is this the case?

According to Latin Times, titles are "either obtained upon birth or bestowed by the reigning monarch during marriage." Additionally, succession is only determined by blood. While gender does not play a part in determining the order of succession, it does play one when it comes to attaining titles.

The rules that have been put into place state that when a male member of the royal family marries his wife she then obtains the female equivalent of his title, which is why Camilla would be able to become queen one day since Charles has the opportunity to be king. However, when a female royal marries her husband, he is not eligible to receive the equivalent.

READ: Princess Diana Didn't Envision Herself Becoming Queen: 'They See Me As A Threat'

As cited by one Quora source in the article, the major difference comes from the fact that there are more varieties of the queen title than there are of king.

"A Queen can be a Queen Consort (married to a King), a Queen Regnant (reigning in her own right), or a Queen Dowager (mother of the reigning monarch). Kings, however, only exist as Kings Regnant (the term isn't particularly used, since that's the only state a King can exist in)," the source explained.

"Therefore, Camilla will be a Queen Consort when Charles succeeds his mother. Philip, on the other hand, can't be a King, since it's his wife (the Queen Regnant) doing the reigning."

This specific rule explains why Catherine, Duchess of Cambridge can someday become queen as well, since she married Prince William and can therefore eventually obtain the equivalent to the title he will likely have himself one day.

Camilla Parker Bowles
Camilla Parker Bowles attends Ladies Day at the Cheltenham Festival at Cheltenham Racecourse on March 13, 2019, in Cheltenham, United Kingdom. Getty Images/Aaron Chown-WPA Pool