While it may be hard to believe, William and Harry were quite close growing up. Their mother, the late Princess Diana, would regularly take the young boys on quite unconventional excursions - or at least unconventional by a royal's standard - reinforcing the importance of family.
It is said that the brothers grew only closer by their mother's tragic death. And even though Prince Harry has had his fair share of scandals over the years - let's not forget the time he was captured naked in a Las Vegas hotel room back in 2012 - for the most part, William stood by his brother through thick and thin.
Although reports say the future king was furious about the hotel room incident, he clearly wasn't angry enough to let the rendezvous ruin their entire brotherhood; no, their feud didn't start until 2016: aka, the year Harry started dating Meghan Markle.
After barely four months of dating Meghan, Prince Harry decided it was time for his new girlfriend to meet his family - a scary step regardless, but even more-so when your grandmother is the Queen of England.
From here, things took a turn for the worst. While Harry was besotted with Meghan, apparently William had his reservations about how quickly things were moving between the couple - and he told his little brother as much once Meghan had returned to her home country of Canada.
According to The Sun, a well-placed source revealed: "William told his brother that they knew nothing about her background, her intentions, what she was really like."
"He just wanted to stress that becoming part of the Royal family is a massive undertaking and the pressure and scrutiny is unrelenting. Was Meghan the right one?"
Suffice to say, William's reservations didn't go down too well with Harry who allegedly went "mental" in his defence of Meghan. The same source claimed: "He accused his brother of trying to finish his romance before it had begun. The brothers' relationship has not really recovered."
When Harry and Meghan eventually got married in 2018, tensions were at an all time high. Not only did Meghan's decision to cut her father off reportedly baffle the Duke of Cambridge, Meghan and Kate's wedding planning arguments were sure to deepen the rift between the two brothers.
While, at the time, it was reported that Kate Middleton made Meghan Markle cry over an incident involving flowergirl dresses, the Duchess of Sussex herself recently claimed to Oprah that this narrative was completely false and, in fact, it was the other way around.
During the now-infamous interview with Oprah Winfrey, the presenter asked Meghan if there was any truth to the rumour that she made Kate cry. (At the time, the story was that a dress fitting for Princess Charlotte's flowergirl dress turned sour, leaving Kate Middleton in tears.)
"No." the former duchess answered Oprah's query with a sigh. "The reverse happened.... A few days before the wedding she was upset about something... and it made me cry and it really hurt my feelings,"
While Meghan assured Oprah that the two women have since mended things, Kate even allegedly purchasing the Duchess flowers as an apology, the same can unfortunately not be said for their husbands.
In 2019, Prince Harry confirmed what the world had been fearing the most... that he and William's relationship was beyond strained.
Speaking in the documentary, Harry and Meghan: An African Journey, Prince Harry confessed that he and the future King were "on different paths".
"Look, we're brothers, we'll always be brothers. We're certainly on different paths at the moment but I'll always be there for him and as I know he'll always be there for me."
It was a bittersweet comment that glass-half-full people saw as providing hope for a future reconciliation and glass-half-empty people saw as dooming the brothers' relationship for good. What happened next, unfortunately, proved the latter group of people right.
Not long after Harry's confession that he and Will were "on different paths", he put his money where his mouth was and took a WILDLY different path to the one he'd grown up knowing.
Indeed, in March 2020, Prince Harry and Meghan Markle stepped back from their duties as senior royals in what was a highly unprecedented move that would further drive a wedge between the Sussexes and the Cambridges - both psychologically and geographically.
The extremely unconventional move, colloquially coined as Megxit, saw Harry and Meghan pack their bags and jet off to Canada for a few weeks, before deciding to reside in LA where they currently live.
The brothers now seemed more far away than ever, but perhaps distance would make the heart grow fonder?
No, absolutely not. Things got a whole lot worse.
The minute Prince Harry and Meghan Markle sat down with Oprah for that bombshell interview and starting dishing A LOT of alleged dirt on the monarchy, it was clear that the brothers were in no way in each other's good books.
In the 90-minute event, the ex-royals bared all to the TV host. At first, it was just Meghan who sat down with her long-time friend, dropping bombshells left right and centre.
It started with the former actress suggesting it was actually Kate who made her cry but, from there, it got progressively darker, with the former Duchess opening up about her harrowing mental health battle, and Prince Harry eventually joining to talk about his strained relationship with William.
Despite all of these revelations, the world was taken with one claim in particular. When Meghan alleged to Oprah that there had been "concerns and conversations about how dark (her son Archie's) skin might be when he was born", the TV presenter's stunned facial expression mirrored the reaction of viewers everywhere.
It didn't take long for Prince William to comment on the accusation.
During a trip a school in London, Prince William and his wife Kate Middleton couldn't escape one particular paparazzo, who took their opportunity to ask the questions that were on everyone's lips.
"Sir, have you spoken to your brother since the interview?" the cameraman asked.
"No, I haven't spoken to him yet but I will do." the Duke replied as he strolled along with Kate and workers from the school.
The paparazzo managed to squeeze in just one more query, one that was on the minds of everyone since the interview aired.
"Can you just let me know, is the royal family a racist family, sir?" they asked.
"We are very much not a racist family." William stated simply before heading off to perform his royal duties.
Ever true to his word, it seems that William did indeed speak to his brother about the interview. But things did not go according to plan.
Speaking to CBS' This Morning, Oprah's friend Gayle (who owned the house where the interview was filmed) revealed that she had invited Harry and Meghan back to her house the weekend after the chat "to see how they were feeling" in the wake of it all.
That is when the couple apparently revealed that Harry had spoken to his brother William as well as his father Prince Charles, yet the talks were "unproductive".
Now, the feuding brothers have been forced to reunite in the saddest of circumstances - their grandfather's death.
After it was announced Prince Philip had passed away on Friday 9th April, 2021, Prince Harry left sunny California and headed back to the UK to be with his family. Noticeably missing was Meghan Markle who is currently in the late stages of pregnancy and was reportedly advised not to travel.
As well as preparing for the funeral, the brothers are allegedly organising a statue of their late mother to be unveiled this July in honour of what would have been her 60th birthday.
Whether or not the brothers will be able to put their differences aside and put up a united front in both of these instances remains to be seen - however sources think it to be unlikely.
An insider told The Sun: "William and Harry are as far apart as possible to be - emotionally and physically. Their relationship is at rock bottom. William's raging with Harry after the Oprah interview.
"He is so angry with him that it's totally unthinkable at the moment for them to be happily reunited and stood together at the unveiling of the Princess Diana statue. It'll take a lot of work to patch things up so they can put on a united front."