A supporter of the Islamic State's (ISIS) militant group admitted encouraging jihadists to attack Prince George in a terrorist attack at the young king's school
Husnain Rashid, 32, of Lancashire in the UK changed his request for two weeks after a trial for multiple terrorist crimes after initially denying all allegations against him
He pleaded guilty to three major charges at London's Woolwich Crown Court for preparing terrorist attacks and promoting terrorism.
Rashid was accused of sharing a picture of the eldest son of Prince William and Kate Middleton with the address of his school in Battersea, London, via the encrypted intelligence service Telegram to his extremists.
One of the images he made of the young king third in the line of succession was a superimposed image of the four-year-old beside a silhouette of two Jihad fighters saying, "Even the royal family is not left alone
During the trial it was heard that Rashid had written more than 300,000 messages via telegram in which he demanded an attack with a lone wolf. The prosecution said Rashid operates a "fertile" telegram channel called Lone Mujahid in which he provides an "e-toolkit for terrorism".
The police said Rashid shared a list of popular British sports stadiums, suggesting injecting poison into supermarket ice cream urged the Jewish areas of the UK to be killed in a terrorist attack.
Rashid has also allegedly posted a map of New York's Sixth Avenue, along with the headline: "New York Halloween Parade you made your preparations? the countdown begins? as well as popular tourist destinations and train stations across Europe.
Sky News reports that the 32-year-old has urged Jihadis to "fight and spill the blood on the monkeys in your country". "Start planning, start exploring destinations, begin monitoring inbound / outbound routes, start preparing tools and weapons / explosives."
Following a change in Rashid's request, Judge Andrew Lees told the defendant, "Last week, I have the most disquieting allegations," the BBC reports.
"They have admitted these accusations of encouraging others to commit terrorist activities and publishing statements to encourage the killing of others."
"It is inevitable that you will receive a very long prison sentence e) and it will be over considered a life imprisonment.
He added: "I have to weigh very carefully the question of your future danger and the protection of the public. "
Rashid will be convicted in the same court for terrorist offenses on June 28.