As the eldest son of Queen Elizabeth II, Charles is the heir to the throne. (AFP Photo)
A "ginger extremist" convicted of plotting to kill Britain's Prince Charles so his red-haired son Harry might become king was on Tuesday was sentenced to indefinite detention.
Mark Colborne, 37, compared himself to the Norwegian extremist Anders Behring Breivik and wrote in his notebook of his plans to "put a bullet in Charles' head", the heir to the throne, to avenge the discrimination that he felt red-heads suffered.
Colborne was convicted in September of preparing terrorist acts and during sentencing on Tuesday, judge John Bevan called him an extraordinarily "warped individual" who displayed "extravagant self-pity".
"You have been consumed with rage at disparate individuals and groups and you write in graphic terms of bombing and butchery," he said.
"You are, I regret to say, a warped individual who in the past has held views of your fellow man which were repugnant to right-thinking people."
Colborne was arrested on June 3 last year after his half-brother discovered papers detailing his racial hatred and chemicals at the family home in Southampton, on the southern English coast.
"I would sacrifice my life for that one shot. Kill Charles and William and Harry become king. Kill the tyrants," he wrote in one entry.
"I want them to see my transition from poor red-haired victimised minority that is constantly walked over to a fully transformed military terrorist," he added.
He got information from the Internet about producing viable explosives and had books containing recipes for producing lethal poisons like cyanide.
Colborne dismissed the diary entries as "angry rants" made when he was off medication for depression.
The judge ordered Colborne to be detained under section 37 of the Mental Health Act "without limit of time" and he is expected to receive treatment for psychosis at a secure unit in Hampshire, southern England.
As the eldest son of Queen Elizabeth II, Charles is the heir to the throne. Second in line is his eldest son Prince William, followed by William's two children, Prince George and Princess Charlotte.
Harry, William's ginger-haired younger brother, is fifth in line.