Meghan, Duchess of Sussex. Picture: Reuters

Meghan, Duchess of Sussex, first started campaigning for feminism at the age of 11.

The 37-year-old former actress - who was known as Meghan Markle before she joined the royal family when she married Prince Harry last year - has said that although she didn't "know what sexism meant" at the time, she knew something was "wrong" when she saw an advertisement for dishwashing soap that declared, "Women all over America are fighting greasy pots and pans."

Speaking at a panel for International Women's Day on Friday, she said: "At age 11, I had seen a commercial at the time that I thought to be very sexist. Truth be told, at 11 I don't think I even knew what sexism meant. I just knew that something struck me internally that was telling me it was wrong, and I knew that it was wrong. And using that as my moral compass and moving through from the age of 11, at that age I was able to change this commercial."

The former 'Suits' star ended up writing a letter to the company who created the commercial, and was successful as they then changed their slogan from "women all over America" to "people all over America."

“If things are wrong and there is a lack of justice, and there is an inequality, then someone needs to say something” — The Duchess of Sussex on #InternationalWomensDay @QueensComTrust #IWD2019

— Kensington Palace (@KensingtonRoyal) March 8, 2019

Meghan added: "It really set up the trajectory for me to say, if there was a wrong, if there is a lack of justice, and there is an inequality, then someone needs to do something. And why not me?"

Ahead of the panel, Meghan - who is currently expecting her first child with Prince Harry - was named as vice president of The Queen's Commonwealth Trust, of which the Queen is Patron and Prince Harry is President. 

The trust exists to champion, fund and connect young leaders around the world, and the Duchess she hopes to bring "equality for all of us" through her role.

She said: "I think, you know, looking at my role, and I'm very, very privileged to have now with the QCT, just expands that platform to be able to go to 53 Commonwealth countries and do this level of work all across the globe because again, it is about global feminism, it is about a parity and equality for all of us. It started at 11, but still feels like it's just beginning!"