Prince Harry can step aside — the OG “spare” is actually Prince Andrew.
A new A&E documentary, “Secrets of Prince Andrew,” has revealed why the scandal-ridden Duke of York has always been considered the late Queen Elizabeth’s “favorite” child as well as the original surplus prince.
“We know from Prince Harry that the ‘spare’ creates an idea of resentment and jealousy,” British biographer Andrew Lownie said.
“[Prince] Andrew was an accident waiting to happen for years.”
The Post has reached out to reps at Buckingham Palace for comment.
Andrew, 63, was always rumored to be the long-reigning monarch’s most loved and most treasured son, despite not being the firstborn.
As the third child of the queen — who died in September 2022 at the age of 96 — and her late husband, Prince Philip, he was second in line to the throne at the time of his birth in 1960.
“His birth was celebrated as he was the next male heir, despite [his sister Princess] Anne being [born] second,” journalist Dickie Arbiter said in the doc. “If [King] Charles died, then Andrew would be the one directly in line to succeed him.”
He added that the queen had already settled into her life as a mother by the time Andrew came along, as she had given birth to Anne in 1950 and Charles just two years earlier.
“Courtiers” author Valentine Low interjected and pointed out how she was an “indulgent” mother to Andrew, and with him, she could “sit back a bit” to enjoy motherhood.
“She was a slightly absent mother to her older children,” Low said.
” ‘I can read him bedtime stories,’ ” the writer noted of what the monarch allegedly said during Andrew’s childhood.
“Charles’ future was ordained and this set up tensions between Andrew and Charles. He thought Andrew had an easier ride at life,” Lownie said.
He remarked how Andrew was a prankster in his youth and “was indulged in the ways that the other children weren’t because boundaries were never set for him.”
“Everyone talks about him not growing up. He’s a sort of Peter Pan figure and has been emotionally stunted,” Lownie said.
Once Charles had his children — Harry, and Prince William — Andrew dipped further and further down the line of succession.
Arbiter also said when the former Prince of Wales welcomed his sons, Andrew’s role as a “spare” was starting to fade into the distance. In the early 1980s — before he married Sarah Ferguson in 1986 — he was having fun and had an eye for the ladies.
“One thing in the royal family is that you don’t show emotion in public,” Arbiter said, adding that when Charles married the late Princess Diana in 1981, Andrew was barely 21 years old.
“This signified that marriage means children and children means that [Andrew] would be dropping down in line of succession. Psychologically, he found that the status as the ‘spare’ was unmistakable,” the royal expert went on.
Andrew had then joined the Royal Navy in 1982 and fought in the Falklands War. He desired to be successful in that endeavor in an attempt to prove himself.
However, their relationship was controversial and the British media was largely unkind to her.
The press “put their claws into her,” Arbiter recalled. “That probably would have been a very good match for Andrew.”
Stark and Andrew’s romance fizzled out, allegedly due to her decision to act in a lesbian shower scene for an adult film.
According to Lownie, Andrew wanted to “settle down” with Stark by 1985, and he was “upset” that their love affair was unable to continue. “He wasn’t allowed to marry the women he loved,” he said.
Once Andrew and Ferguson — also affectionately known as Fergie — tied the knot in 1986, and they welcomed their daughters Princess Beatrice and Princess Eugenie in later years, life seemed blissful for a time.
“The queen loved the idea that her son got married,” Arbiter said of the nuptials. But Fergie and Andrew had their issues behind the scenes and announced their separation in 1992.
According to the documentary, the former Weight Watchers spokesmodel saw her husband only a few times out of the year and was fed up with being the devoted wife.
Their marriage came to a screeching halt when photos of Fergie’s toes being sucked by her financial advisor John Bryan while on vacation were published in the newspapers in 1992.
“[With those pictures], Fergie was sacrificed at the altar of tabloids in order to protect other members of the royal family,” screenwriter Daisy Goodwin said.
“Because Andrew and Sarah were farther down the line of succession, they were fair game [in terms of] dirt on them. They were not going to bring down the monarchy,” she explained.
Following their divorce, Andrew and Fergie have stayed friends — even living together at their longtime home, the Royal Lodge.
Andrew’s scandals, such as his affiliation with dead convicted pedophile Jeffrey Epstein, as well as the past lawsuit filed against him by victim Virginia Roberts Giuffre, have plagued much of his life.
The doc also notes that when his mother died, Andrew lost her as his “safety net” regarding the various accusations against him.
“Her death was almost unimaginable and the whole nation sort of thought that she would live forever,” Goodwin said.
“Andrew’s life is going to be much harder now that the queen is dead. She was his champion and was the person who found him irresistible,” she said.
The “Victoria” creator added: “Charles clearly finds him unsympathetic, and Andrew doesn’t have a lot of friends left in the royal family.”
“Secrets of Prince Andrew” premieres Monday, Aug. 21 on A&E.