There are many questions about this modern Royal relationship

So it happened.

The engagement announcement we had all been expecting since the couple appeared before us in Toronto in September, was made this morning.

It turns out Prince Harry proposed in London earlier this month.

So who is Meghan Markle and how did a divorced American actress end up engaged to such a prominent member of the Royal Family?

Meghan and Harry first stepped out before the cameras as a couple in September.

They had met more than a year earlier at the private members’ club, Soho House, in London.

Soho House in London where Prince Harry met Meghan Markle

Meghan had a friend who managed the chain of clubs - and she met Prince Harry there in the summer of 2016.

Her acting career involved other TV shows, but it was her role as the young trainee lawyer Rachel Zane in the US TV series Suits which catapulted her to fame.　

But when the story of their romance hit the front pages last Autumn things became immediately difficult.

Prince Harry was alarmed at the way newspapers were looking into Meghan's family, her ex-boyfriends and her past life.

He authorised a strongly worded letter - highly unusual from one of the royal palaces.

"The past week has seen a line crossed," it read. "His girlfriend, Meghan Markle, has been subject to a wave of abuse and harassment."

The statement went on: "He knows commentators will say this is 'the price she has to pay' and that 'this is all part of the game'. He strongly disagrees. This is not a game - it is her life and his."

It showed how serious the Prince was about this relationship.

The pair appeared in public in the gardens of Kensington Palace on Monday afternoon, just hours after the engagement was announced. Credit: PA

There were very few pictures of the couple after that.

Some were taken at a polo match in Berkshire – others showed the couple buying a Christmas tree together.

But they were the exception rather than the rule.

When Prince Williams' sister-in-law got married earlier this year - there was a lot of talk about whether Harry's girlfriend should come.

At the wedding of Pippa Middleton in May, Harry and Meghan were nearly year into their relationship.

Harry attended Pippa Middleton's wedding in May without Meghan Markle Credit: PA

It was decided Harry would come alone to the ceremony in Berkshire.But they would appear as a couple at the marquee reception at the Middleton family home.

So Meghan did attend that night as Harry's plus one.

But by now Meghan Markle was committed to filming Series 7 of her TV drama.

Suits might be about a New York law firm - but it is actually filmed on location in Toronto in Canada.

The same city which was - in September - planning to host Prince Harry's Invictus Games.

Before the Games got underway, Meghan Markle, with Harry's knowledge, gave an interview to the magazine Vanity Fair from her Toronto home.

Inside she referred to Harry as her boyfriend and said "We are two people who are really happy and in love. We were very quietly dating for about 6 months before it became news".

At the end of September, as Prince Harry welcomed the 550 competitors at the opening ceremony, the photographers in the room discovered that Meghan Markle was also there.

Meghan Markle and Prince Harry at the Toronto Invictus Games Credit: PA

Meghan was watching from the stands, sitting next to Markus Anderson - the man who had introduced her to Prince Harry at the Soho House club - nearly 18 months before.

And that meant just two days later the stage had been set for them to appear as a couple in front of the world's press.

There are many questions about this modern royal relationship.

Will Ms Markle now put her acting career permanently on hold?

Will this transatlantic couple now settle over here?

Will it be a different kind of royal wedding - and who will be invited?

They are all questions to which we will get answers - but for now they are just a couple looking forward to their wedding in the Spring of next year.