DALIBOR JÍLEK – JANA MICHALIČKOVÁ CYIL 7 ȍ2016Ȏ convergent or interchangeable in the doctrine, legislation and judicial decisions. As shown, the content of both concepts are interdependent. The concept of habitual residence was inserted into the law of the Communities in its very early development. At that time the Community law was also regarded as a branch of international law. It appears that historical deeds and affairs are repeating. The concept of habitual residence was first used in social law. From this field it penetrated into tax law and law of staff. It was not defined in any of the secondary acts. The Court of Justice explained the content of the concept of habitual residence in the Angenieux case by ostensive definition. The Court gave the concept a common role. After that the concept was taken by family law. It started to be used in various sources: international convention and regulations relating to parental responsibility and child protection. In the case Proceedings brought by A the Court did not apply the ostensive definition of habitual residence. It delimitated the factual concept of habitual residence based on the descriptive definition instead. Diachronic observation of the development of the factual concept of habitual residence in different legal domains supports the hypothesis that the role of the concept determines its content.