Children and minors who committed an offence in European history have had always a special position, although principles of criminal liability were different. Children and minors in criminal law have always been treated differently than adult criminal offenders. But there were changes in age limits for defining children and minors, in defining different age groups and in treating before the court. But the beginning of 20th century was a turning point in criminal law – the beginning of juvenile criminal justice and juvenile law. Thanks to Fran Milčinski Ljubljana had an important role in this area. From 1930 on Slovenian children under the age of fourteen are no longer treated as be criminal offenders.