The main subject of this article is the World legal history researches made from 19th to the middle of the 20th century, the formation and the development of the research schools on law history. There were early manifestations of the interest toward the law of the past – especially on the Roman law during the time of The Middle Ages: first in Byzantium, but later in Western Europe. Some overall researches on the law history appeared in 16th - 18th c. The real research work on the World legal history began in 19th century. Just at that time, the research schools were set up. The general concept, which lies in the base of this article is, that the factors which formed different research schools were previously political, not juridical. The interest of the research workers depended on the interest of their societies.
Thus, the English and French scholars explored the legal history of most of the countries and the nations, because England and France were powerful colonial empires. Unlike them, the German and Italian scholars directed their attention to their national legal systems and the Roman law – the two countries were separated and they endeavoured to national unification; they had no colonial possessions. Russian and other Slavonic researchers were under the influence of different ideological theories – Slavyanofilstvo and Panslavism. That is why they studied their national and Slavonic law. The other contribution of the article is the wide and detailed bibliography preview of hundreds of authors and hundreds of publications in five languages – English, French, German, Italian and Russian. A definition of the essence of law history research school has been given here. At the end, there is a short preview of research works on the World legal history in Bulgarian.