Six children were held hostage in house siege
Michael Roland Page barricaded himself into a house in Keightley Road, New Parks, armed with a hammer.
He threatened the children would get hurt if the police forced their way in.
The 37-year-old originally denied falsely imprisoning the three boys and three girls, aged between four and 16.
However, he changed his pleas to guilty yesterday, moments before his trial was due to begin at Leicester Crown Court.
Page, who has a history of mental health problems, was unwell at the time of the two-hour siege on August 18 last year, the court heard.
In the light of his guilty pleas, the Crown Prosecution Service dropped two allegations of assault, which he continued to deny.
Sarah Knight, prosecuting, said she understood Page now conceded "there was a hammer to hand" during the siege.
She said: "He accepts he said that, if the police forced an entry, the children would get hurt.
"He accepts there was an element of threat or fear.
"He has admitted the serious element of the Crown's case and ensured these young witnesses aren't put through the anguish of giving evidence in court."
Judge Simon Hammond said: "The children were in the living room and it must have been very frightening for them."
Sentencing was adjourned until May 22 for the preparation of pre-sentence and psychiatric reports.
When the siege took place, the defendant was on early release from a six-year jail term imposed in 2006 for blackmail, attempted robbery and assault.
He has since been returned to jail to serve the unexpired licence period.
Judge Hammond said: "The advantage of having pleaded guilty means six children don't have to give evidence and, albeit you entered them late in the day, you'll get credit for that.
"It's a worrying case and it's obvious you were unwell.
"You told the police at the time they should contact your mental health team."
At the time of the incident, the Leicester Mercury reported that the siege was triggered by a domestic dispute with his then partner at home.
Police negotiators eventually persuaded Page to release the young hostages.
Armed officers later stormed in and arrested the defendant.
Three of the children were said to have lived in the house and three others were believed to be the children of neighbours.
The mother of a 13-year-old male victim said on the day: "The kids are all shaken and scared by this.
"It all happened so quick. I tried to get the man to give himself up, but he barricaded the front room with a sofa.
"I wanted to exchange myself for my lad, but the police were having none of it."
