Prince Harry and Meghan Markle's ultra-private marriage away from the cameras after May 2018 wedding

The Duke and Duchess of Sussex are set to reveal more behind-the-scenes details about their relationship than ever before in their upcoming Netflix documentary, Harry & Meghan.

Their love story began in the summer of 2016 when they began secretly dating after being set up by a friend, and six years later they are happily married with two children Archie and Lilibet, and living in the United States. During their eventful few years as husband and wife, they have shared snippets of what makes their bond so strong – take a look inside Prince Harry and Meghan Markle's marriage secrets.

WATCH: Hello! Insider: Harry and Meghan's Oprah Interview

When did Prince Harry and Meghan Markle get married?

The royal couple announced their engagement in November 2017 before exchanging vows the following spring. Their royal wedding took place at St George's Chapel in Windsor Castle on 19 May 2018, with the beautiful bride wearing a bespoke Givenchy bridal gown before changing into a more daring halterneck Stella McCartney dress for the evening reception at Frogmore Hall.

1. Learn about each other

The royals began secretly dating in 2016

Prince Harry and Meghan have opened up about the shock of intense media interest in their relationship, but they have both admitted that they didn't have any preconceived ideas about one another. Instead, they took the time to build their opinions in person without the influence of the press, they said during their engagement interview.

The Duke admitted he'd "never watched Suits" and the Duchess said: "Because I'm from the states you don't grow up with the same understanding of the royal family."

Speaking of the "refreshing" way their relationship developed, Meghan explained: "Everything I knew about him and his family was what he would share with me and vice versa, so for both of us, it was just a really authentic and organic way to get to know each other."

With people "thinking they know" a lot about Harry, he reiterated it was "hugely refreshing to be able to get to know someone who isn't necessarily within your circle". He continued: "To be able to start almost afresh, right from the beginning and getting to know each other step by step."

2. Always support one another

It goes without saying that there are too many examples to count when it comes to Harry and Meghan's unwavering support for one another.

Before their royal wedding in 2018, Kensington Palace released a statement regarding the media frenzy, saying: "Prince Harry is worried about Ms. Markle's safety and is deeply disappointed that he has not been able to protect her."

Meanwhile, in 2017 Meghan opened up about how she dealt with being in a high-profile relationship. "It has its challenges, and it comes in waves—some days it can feel more challenging than others," she told Vanity Fair. "But I still have this support system all around me, and, of course, my boyfriend’s support."

The royals got married in 2018

After they tied the knot in 2018, their mutual support system continued – especially amid their exit from royal life in 2020. During their interview with Oprah Winfrey in 2021, Harry told Oprah: "I'm just really relieved and happy to be sitting here, talking to you, with my wife by my side, because I can't begin to imagine what it must have been like for her, going through this process by herself, all those years ago.

"Because it has been unbelievably tough for the two of us, but at least we had each other."

GET SHOPPING: 11 wedding dresses that look like Meghan Markle's Givenchy and Stella McCartney gowns

3. Be open about health struggles

Like many royals, Meghan and Harry vowed to love one another "in sickness and in health", and they're stronger because of their honesty with one another.

One of the biggest bombshells that came out of the couple's interview with Oprah was Meghan's confession about her mental health struggles during her pregnancy with Archie, which she kept private from the public at the time.

Speaking about her time as a royal, the Duchess said that she confided in Harry about the toll the negative media attention was having on her health – and revealed he ultimately "saved all of us."

"Look, I was really ashamed to say it at the time and ashamed to have to admit it to Harry, especially, because I know how much loss he has suffered, but I knew that if I didn’t say it, then I would do it," Meghan told Oprah. "I just didn’t want to be alive anymore."

Meghan had asked The Firm to seek professional help but that support was not available to her. She said she later reached out to one of the best friends of the late Diana, Princess of Wales.

This contributed to their decision to step down as senior members of the royal family and relocate their family to the US. Harry added that Meghan "saved" him "without question", but his wife disagreed and said that Harry made a decision that "certainly saved my life and saved all of us".

If you have been affected by this and wish to seek help, Samaritans (116 123) operates a 24-hour service available every day of the year. If you prefer to write down how you're feeling, or if you're worried about being overheard on the phone, you can email Samaritans at jo@samaritans.org.

4. Privacy is key

The Duke and Duchess moved their family to Montecito

Just look at the start of their relationship for proof! The Duke and Duchess were keen to keep their blossoming romance private for as long as possible, with Meghan telling Vanity Fair: "We were very quietly dating for about six months before it became news, and I was working during that whole time, and the only thing that changed was people’s perception. Nothing about me changed. I’m still the same person that I am, and I’ve never defined myself by my relationship."

She added: "We’re in love. I’m sure there will be a time when we will have to come forward and present ourselves and have stories to tell, but I hope what people will understand is that this is our time. This is for us. It’s part of what makes it so special, that it’s just ours. But we’re happy. Personally, I love a great love story."

The couple even managed to keep their honeymoon a secret to this day.

The Duke and Duchess also wanted to move away from the spotlight after starting a family and chose to purchase a property in Santa Barbara, California in June 2020. Estimated to be worth £11.2 million, their home is located in Montecito, a neighbourhood renowned for its secluded hillside estates that promise the utmost privacy for the couple and their two children.

RELATED: Princess Kate and Prince William divulge marriage secrets: From in-laws to dates

5. Family dynamics aren't always perfect

Meghan has opened up about her relationship with her in-laws

Both Meghan and Harry were very close to their families when they first began dating, and they have formed relationships with their in-laws since then. The Duchess revealed she appreciated her husband's sweet tribute to his late mother Diana with her engagement ring, which features stones from the Princess of Wales' private collection.

She told the BBC: "I think everything about Harry’s thoughtfulness and the inclusion of [Princess Diana’s stones] and obviously not being able to meet his mom, it’s so important to me to know that she’s a part of this with us ... It’s incredibly special to be able to have this [ring]."

Meanwhile, Prince Charles' wife the Duchess of Cornwall previously said: "America's loss is our gain," and Meghan revealed the Queen has always been "warm and inviting".

While there are lots of heartwarming stories about the couple's bond with one another's family, they have also highlighted the realistic and relatable side of family disagreements.

Asked by Oprah why the couple stepped back from royal duties and left the UK, Harry blamed a "lack of support and lack of understanding", but clarified he did not "blindside" the Queen with their announcement.

The Duke also said that his father, the Prince of Wales, had stopped taking his phone calls during the lead-up to their announcement about stepping back as senior royals. When Oprah asked Harry how they were getting along now, the Duke said there was "a lot to work through," adding that he feels "really left down" since they have been through something similar.

Nonetheless, the Duke went on to say that he will "always love him" and will continue to make healing their relationship "a priority" while referring to Charles' role as Archie's grandfather.

6. Date night is crucial

Even before they welcomed their two young children, the couple proved they always carved out some one-on-one time together. The boutique Dean Street townhouse will always hold fond memories for Harry and Meghan as there's where the pair were set up on their first date in summer 2016. Finding Freedom says it was one of the couple's "tried-and-true spots" that they liked to venture out to in London during their first year of dating.

Weeks before Archie arrived they slipped out to see Tina: The Musical in London and had a babymoon in Heckfield Place, an exclusive Hampshire hotel, where suites are up to £10,000 per night.

UP NEXT: Concealed royal wedding shoes: Queen Consort's colourful heels, Meghan Markle's skyscrapers and more

Planning your wedding? Sign up to HELLO!’s brand new Bride Guide newsletter for expert advice, budget help, wedding inspiration and real life stories delivered straight to your inbox.