Harry, 36, and Margaret, who died in 2002 at age 71, were both born into their families as the "spare," as they were the second-born child, making their older sibling the heir to the throne. And since they were far removed from the ultimate responsibility of leading the monarchy, both royals enjoyed lives filled with rebellion and unconventional romance.
The Countess of Snowden found love with the divorced Peter Townsend; however, he was an unorthodox suitor for Margaret due to his past marriage. Meanwhile, Harry's love interest, Meghan Markle, didn't fit the royal mold either, as she was an American actress and the first person of color in the royal family.
Despite the similarities between the royals' troubled romances, their love stories came to two completely different endings.
Margaret needed Parliament's approval of her engagement to Townsend. When she realized she would never have their consent, Margaret called off their engagement.
"Margaret put duty before herself," royal biographer Andrew Morton, the author of the recently released book Elizabeth & Margaret: the Intimate World of the Windsor Sisters, told PEOPLE.
On the other hand, Harry chose love, with him and Meghan stepping away from their senior royal duties last year to start their lives anew in California. While taking on Hollywood — they signed two multi-million dollar deals with Netflix and Spotify — the Duke and Duchess of Sussex turned on the royal family on national television during their Oprah Winfrey interview last month.
During their bombshell tell-all, the couple cited the royals' lack of support as the reason they decided to step back. They also accused unnamed members of the family of making racist remarks and claimed the institution failed to help Meghan when she was experiencing suicidal thoughts as a working member.
"The wheel turns, 70 years later, and we have another couple having to make a decision: Do they put duty first or their own ambitions and desires first? And they put their own ambitions and desires first," Morton continued. "That is the change we have witnessed during the Queen's reign."
The biographer also pointed out similarities between Harry's relationship with Prince William and Margaret's with the Queen. "In both cases you have one sibling who pushes boundaries, while the other is more serious, more cautious," Morton stated.
In both situations, the undeniable royal "pecking order," as Morton explained it, inevitably hindered the siblings' dynamic.
"At one point, William and Harry were both part of the main branch of monarchy," said the author. "Then William marries and has children, and his children take precedence. Whereas Harry is an ancillary branch in exactly the same way as Margaret."