Prince Charles was supposed to have been made the governor-general of Australia in the 1970s, but apparently Queen Elizabeth rejected the idea of giving him an important position because the Prince of Wales was still not married. 

Old letters from Queen Elizabeth, written through her private secretary, Sir Martin Charteris, show that Her Majesty was allegedly hesitant to name her son because he didn't have a wife. Apparently, it would not have been a good look for the governor-general to be performing his duties without a woman by his side.

At that time, Prince Charles was still in his late 20s and enjoying his bachelorhood. He didn't get married to his first wife, Lady Diana Spencer, until 1981. 

The letter is part of a previously unreleased document that also contained now-declassified information about the firing of Australian Prime Minister Gough Whitlam by Governor-General John Kerr. While some believed that Queen Elizabeth had knowledge of this crucial constitutional crisis in Australia's political history, it has become apparent that Her Majesty was kept in the dark by Kerr's actions. 

Whitman's firing angered many Australians and strained the country's diplomatic ties with Britain. The letter also showed that while the Queen was out of the loop, she had considered dismissing Whitlam or dissolving the Australian parliament. 

Kerr allegedly wrote Charteris that he had fired Whitman without informing the Queen first because it would be better that she didn't know ahead of time. Historians said that Australian never really got to know the full story of this political crisis because the letters were sealed in the National Archives of Australia until recently.  

Meanwhile, Prince Charles was also barred from buying a property in Australia by his mother. Another letter from Charteris stated that it would not look good if the Prince of Wales were to splurge while there was an economic and housing crisis going on in Britain. 

Charteris further wrote that there was "never a good time" for royals to make showy purchases, adding that the timing of a land purchase could spark another public outrage. 

Meanwhile, Prince Charles and his young wife, Princess Diana, did visit Australia when Prince William was still a baby in 1983. While Prince Charles' popularity with the Australians often waxed and waned, they fully embraced his wife. 

This sparked early rumors of problems with the coupling as Princess Diana apparently overshadowed her husband, the future king. Many royal observers believe that the decline of their marriage started during their first Australian tour.