The first part of the work is devoted to the consideration and analysis of the main definitions of the main categories of the Indian legal system and the periodization of its historical development, which have developed in theoretical and historical legal sciences from the end of the 18th century up to the present time. It has been established that the categorical apparatus applicable to the realities of the Indian legal system uses definitions from legal theory and comparative law, which note its mixed or hybrid nature. The history of the emergence of the term "Hindu law" is also examined in connection with its characterization as a religious legal system given by the English colonial authorities during the legal reforms of the late 18th to the first half of the 19th century.