British Prime Minister David Cameron has begun the process of trying to reform outdated and controversial Royal succession laws that favour males over their older sisters as heirs to the throne.

Cameron has written to Prime Minister Stephen Harper and the heads of 14 other Commonwealth countries in order to solicit their opinions on updating the law.

Any such change would require unanimous consent from all 16 Commonwealth countries.

Under the 1701 Act of Settlement, a male heir takes precedence over any older female siblings, and would typically leapfrog his older sisters to the throne.

That means that if Prince William and the Duchess of Cambridge have a daughter as their first child, she would only have a claim to the throne as long as she had no younger brothers.

Under Cameron's proposal to modernize the rules, the royal couple's first child would become the heir regardless of gender.

Cameron said the antiquated laws simply don't fit with the values that the Commonwealth holds dear.

"We espouse gender equality in all other aspects of life and it is an anomaly that in the rules relating to the highest public office we continue to enshrine male superiority," Cameron wrote in his letter.

In another proposed update to the succession laws, British monarchs would no longer be banned from marrying Roman Catholics.

The issues are expected to be on the table when Cameron meets with Commonwealth leaders in Australia later this month.

Previous leaders have tried to update the succession laws, but were unsuccessful. Former prime ministers Tony Blair and John Major both looked at the issue, but nothing developed. British lawmaker Keith Vaz also recently led a debate on the subject in the British House of Commons.

"Gender equality has been the cornerstone of British society for more than 35 years," Vaz wrote in a statement on his website, calling for change prior to William and Kate's wedding.

"It seems only fair that this is reflected in Royal Succession rules and with the marriage of Prince William and Catherine Middleton less than 100 days away this is the right time to bring these rules in line with 21st century Britain."

Interestingly, it's the Act of Settlement that may have prevented Britain from forming an alliance with Germany's Second Reich just a few years before the Great War.

Wilhelm II of Germany, known as the Kaiser, was the grandson of Queen Victoria. Her eldest child -- Wilhelm's mother the Princess Royal -- was leapfrogged by her younger brother who went on to become Edward VII.

The Princess Royal later married Prince Friedrich Wilhelm of Prussia at 17, and gave birth to her son Wilhelm who would go on to become the Kaiser.

If the Act of Settlement hadn't been in place, the Princess Royal wouldn't have been leapfrogged by her younger brother to the British throne.

She would have been queen, and as a result when she died in 1901 her oldest son would have succeeded her.

That was the Kaiser, who by that time was Emperor of Germany, and theoretically could have extended Germany's empire to include Great Britain.

A few years later in 1914 when the Great War broke out, Britain could have been allied with Germany.