The term Kshatriya refers to the warrior caste in the traditional Indian caste system. The term 'warrior' in this context covers the aristocratic or landowning ruling classes, including kings.
It is sometimes claimed that the Kshatriya caste was originally the highest caste before the Brahmins took over that status. Because caste is determined by familial inheritance, actual historical rulers and ruling dynasties are not necessarily of Kshatriya caste, since many obtained power by conquest or other similar means.