Prince Harry struggled significantly without his brother around, resorting to "excessive" drug use while left alone, according to a royal expert.
In his 2020 book Battle of Brothers, royal historian Robert Lacey detailed how the then-15-year-old Harry began to spiral after his 18-year-old brother William graduated from Eton and went on a gap-year trip to Belize, leaving Harry behind.
"Lonely and left to his own devices, Harry began getting stoned to excess, continuing his pot-smoking throughout William's absence in 2001, until someone — a member of the Highgrove staff, it is thought — told Prince Charles what was going on," Lacey wrote.
Harry revealed that he began smoking marijuana while at Eton, earning the nickname 'Hash Harry' from his classmates due to the frequent smoky smell from his room.
The situation worsened after his brother's departure. In his memoir Spare and related interviews, Harry disclosed his experiences with cocaine, magic mushrooms, and marijuana, as well as psychedelics like ayahuasca, which he used as a form of therapy.
He described his early introduction to marijuana during his time at Eton College, near Windsor Castle.
Writing about his introduction to marijuana when he was a schoolboy at the prestigious Eton College near Windsor Castle, Harry said: "I don't remember how we got the stuff. One of my mates, I expect. Or maybe several.
He also spoke about his experiences with cocaine: "At someone's country house, during a shooting weekend, I'd been offered a line, and I'd done a few more since.
"It wasn't much fun, and it didn't make me particularly happy, as it seemed to make everyone around me, but it did make me feel different, and that was the main goal. Feel. Different. I was a deeply unhappy 17-year-old boy willing to try almost anything that would alter the status quo. That was what I told myself anyway."
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