In a frightening revelation, witnesses recalled that the 98-year-old was "rough" with his son, and "frequently reduced the boy to tears."
It is likely that the Prince of Wales developed an incredibly toxic relationship with his father.
"Charles was frightened of his father and always desperate to please him, without ever apparently succeeding," wrote Junor.
The Royal expert believes the 70-year-old remains afraid of his father to this day.
"Charles is still eager to please his parents and earn their approval, and much of the time still feels he’s failing," Junor revealed sadly.
Prince Philip allegedly made consistent biting remarks towards his son and to this day does not hold him in high regard, turning Charles into a fragile shell of a man.
"It is hard to feel anything else when your father repeatedly makes sarcastic and cutting comments either to you or about you."
WATCH: Prince Philip's most offensive statements
In Philip's eyes, Charles' was a constant disappointment, and their relationship has remained fractured as a result.
"He wanted a son in his own image – a tough, abrasive, plain-talking, unemotional man’s man – but those qualities bypassed his first son," wrote Junor.
Unfortunately for Charles, his father seems to favour little brother Andrew for the very reason he doesn't care for his eldest son.
Royal journalist Sue Arnold has claimed that Philip admires the Duke of York for his 'action-man image': "Prince Philip admires Andrew’s macho action-man image – it reminds him of his own youth."