Elton John wrote his most popular song of all time as a way to escape a romance gone wrong.

The Rocket Man just launched his new Disney+ documentary, Elton John: Never Too Late, in which he discusses a relationship that broke his heart to the extent of creating 1973's "Candle In The Wind" (which went on to sell over 33 million copies worldwide upon its re-release in 1997 as an ode to the late Princess Diana).

The "I'm Still Standing" hitmaker dated his manager, John Reid, for five years beginning in 1970. The relationship saw the height of John's career with the release of Goodbye Yellow Brick Road in 1973, featuring the aforementioned track that was penned as a way to escape his crumbling relationship with the storied manager.

"It was the same time John Reid broke my heart. My relationship with him wasn’t all it was meant to be. When I wrote those songs I was miserably unhappy. That kind of came through in the songwriting. It was very very moving to me, and it was very very cathartic."

The 77-year-old superstar revealed that Reid not only cheated on him, but struck his face once during an argument.

"I was very naive. I didn’t know that he was having sex outside the relationship. When I found out about it, I was crushed. I had a party at the house, and we had a fight, and he smacked me in the face. He made my nose bleed, cut my face. I loved John a lot, but I said, ‘I can’t go through this anymore.’ And when that fell apart, I kind of fell apart."

A year before they broke up, John was introduced to cocaine and admitted to becoming addicted to the drug as he desperately sought joy and was "going the wrong way about it."

The pair split in 1975 and Reid remained John's manager until 1998, per People. The "Your Song" standout married husband David Furnish in 2014. The couple are extremely happy together and share sons Zachary, 14, and Elijah, 11.

For more on Elton John and David Furnish's relationship timeline read: Elton John & Husband David Furnish Reveal The First Meal They Ever Shared.

If you or someone you know is struggling with addiction there is help. Contact the Suicide & Crisis Lifeline by dialing 988 or visit 988lifeline.org.

Melissa Forman in the Morning