The other married woman Edward VIII was devoted to before Wallis Simpson

When King Edward VIII abdicated from the throne in 1936, he nearly brought down the British monarchy, and changed the course of royal history forever.

The then-monarch had fallen in love with Wallis Simpson, a woman soon to be divorced twice, and he intended to marry her.

However, as marrying someone who was divorced was not permitted by the Church of England, and the fact that he was the head of the church, forced Edward to abdicate in order to be able to marry the woman he loved.

“You must believe me when I tell you that I have found it impossible to carry the heavy burden of responsibility and to discharge my duties as King as I would wish to do without the help and support of the woman I love,” Edward stated in his abdication speech.

The couple went on to wed Wallis in 1937, and they remained together until his death in 1972.

But what some might not know, before Edward fell for Wallis he was embroiled in a 16-year long affair with another married woman – Freda Dudley Ward.

Freda married William Dudley Ward, an emerging Liberal politician, in 1913 when she was 18 years old.

The couple went on to have two daughters together – Penelope and Angie.

Freda and the heir to the British throne began their affair in 1918, and soon became utterly besotted with one another.

According to the biography, Before Wallis: Edward VIII’s Other Women, by Rachel Trethewey, Edward's passion for Freda was "all-consuming".

They were together as much as possible and when they weren't, he would call her "four or five times a night".

Similarly when the then Prince of Wales was overseas on duty, he would write detailed letters to his married mistress, referring to Freda as "my angel" and signed them saying "tons and tons of love from your E".

Edward wanted to marry Freda to "be with [her] always", but to her the idea was totally absurd.

The couple did, however, enjoy socialising on the London circuit and their affair was widely known of in high society.

Towards the end of the 1920s, Edward began an affair with a twice-married American woman named Thelma Furness while also continuing to see Freda.

Edward's mistress eventually divorced her husband in 1931, but it was just a little too late.

The other mistress, Thelma, had introduced Edward to Wallis Simpson that same year.

Freda enjoyed Edward's company for a few more years, but her affair with the Prince eventually ended very abruptly in 1934.

She called St. James's Palace after not hearing from Edward a few weeks only to be met with the operator saying, "I have orders not to put you through."

Freda and Edward never spoke again.

She went on to marry Pedro Jose Isidro Manuel Ricardo Mones, a Spanish marquess, in 1937 but they eventually divorced in 1954.

And, of course, as royal fans will know Edward abdicated from the throne in order to marry Wallis.

Given the titles the Duke and Duchess of Windsor, the couple were exiled to France.

Edward's younger brother, Prince Albert, became known as King George VI and he was then succeeded by his daughter, the now Queen Elizabeth II.