A British man who fathered seven children by raping his two daughters was jailed for life on in a case described by the judge as the worst he had ever seen. The 56-year-old man, who cannot be named for legal reasons, made his daughters pregnant 19 times over a 25-year period of abuse.He was jailed for life at Sheffield Crown Court in northern England and must serve a minimum 19 and a half years. Judge Alan Goldsack ordered him to serve 25 life sentences concurrently.In court last month, the Sheffield man admitted 25 rapes and four indecent assaults.He made his elder daughter pregnant seven times, fathering two surviving children by her. Two other babies died the day they were born. He made his younger daughter pregnant 12 times.She has five surviving children.The case bears similarities to that of Austrian Josef Fritzl, who fathered seven children with his daughter, whom he kept locked in a dungeon for 24 years, before being discovered in April.The court heard how the man terrified his children and locked them up when he was away.The daughters said in a statement through the police: "His detention in prison brings us only the knowledge that he cannot physically touch us again."The suffering he caused will continue for many years and we must now concentrate our thoughts on finding the strength to rebuild our lives."The man, who refused to attend the hearing, took pleasure in fathering children by his daughters and threatened to beat them if they refused to have sex with him, the court heard.