Husnain Rashid went on the app Telegram and posted a photo of George with silhouettes of jihadist fighters superimposed on it, along with specifics of his school's address

Prince George started a new school in September, but the exciting time took a dark turn when a British ISIS supporter shared information about the school’s whereabouts and threatened the royal family.

Husnain Rashid went on the messaging app Telegram in October and posted a photo of George, 4, with silhouettes of jihadist fighters superimposed on it, along with specifics of his school’s address. He added a warning: “Even the royal family will not be left alone. School starts early.”

Prince George’s school, Thomas’s Battersea in London.
| Credit: Jonathan Brady/PA Wire
Prince William sees Prince George off to school on September 7.
| Credit: Richard Pohle/The Times/PA Wire

Rashid, 32, was arrested in November at his Nelson home in northwest England, and denied all charges relating to encouraging terrorism and preparing acts of terrorism when his trial started last week. On Thursday at Woolwich Crown Court, however, he changed his plea to guilty, admitting to carrying out numerous terror offenses, such as encouraging terrorism and engaging in conduct in preparation for terrorist acts.

RELATED VIDEO: What Prince George’s Classmates Will Call Him at School — and the Last Name He’ll Use

“You have admitted these allegations of encouraging others to commit terrorist activities and publishing statements to encourage the killing of others,” Judge Andrew Lees said to Rashid, according to the New York Times. “It is inevitable that you will receive a very lengthy prison sentence and there will be a consideration of a life prison sentence.”

The mosque teacher, who went by “Lone Mujahid” online, additionally encouraged violence on British Army bases, soccer stadiums, polling booths, Jewish facilities and the Wimbledon tennis tournament. He also allegedly researched how to go to Syria to join and fight for ISIS, and suggested poisoning fruit and ice cream in supermarkets. Rashid is set to be sentenced on June 28.