Gozoku (local ruling family) (豪族)
Gozoku refers to a family who existed within a broader-based political power of a nation, lords and so on, had many lands, properties and private soldiers in a region, and had a certain level of regional sovereignty. The source of regional sovereignty was its own properties and military force, and the Chihokan (a local official) whose power substantially derived from the authority in a broader-based political power was not called Gozoku. However, each category of Chihokan and Gozoku was not exclusive, and in many cases, the same person was categorized as both Chihokan and Gozoku or moved between the two categories. This is because the broader-based political power incorporated a class of Gozoku into their administration in order to stabilize the political power, or adversely Chihokan became Gozoku when the ruling power of the broader-based political administration weakened.
Japanese history
In the Japanese history, as a historical term, a local chief class and local power clan until the Kofun period (tumulus period) and the Yamato period were called Gozoku. Examples are the Mononobe clan, the Soga clan, the Kose clan, the Heguri clan and others. The sites of Gozoku residences surrounded by moats, including residences, communities, facilities for rites and festivals and so on were excavated. The Yamato Dynasty was actually a coalition government by Gozoku being presided over by an Okimi (great king), especially Gozoku living in Yamato, and since any dispute over succession to the post of Okimi was conducted by the Gozoku's military power, a consequence depended on the stances of more than one Gozoku. Thereafter, due to the introduction of the ritsuryo system (the system of centralized government based on the ritsuryo code), governing regions by bureaucrats who were appointed by the imperial court and to transform Gozoku who lived in the capital into court nobles were planed, and at the same time, some of Gozoku became nobles in charge of the nucleus of the government, and some became middle and low-ranking officials for practical works in charge of governmental bureaucratic structure of the central government. Many of Gozoku who were belonging to the local chief class were transformed into the class of Gunji (local magistrates), and reigned over regions under the supervision of Kokushi (provincial governor) who was dispatched from the central government. This is how the word 'Gozoku' as a historical term disappeared from the front stage of historical description. The local governance by Kokushi under the ritsuryo system relied on a cooperative relationship with the class of Gunji, who ruled with the authority of ancient chieftainship over people, but this authority declined gradually along with fraying of the ritsuryo system in the early Heian period.
People who directly took hold and control of people in the local society instead, were those in the wealthy class and the powerful farmer class who grew from the younger people of class of former Gunji and native Kokushi and so on, and came to conduct a large-scale farmland management in the qualifications of Tato (a field manager) or Fumyo (a local tax manager), and they came to be controlled by Zuryo who was a head of Kokushi transferred to the locale. Samurai appeared along with this change in the structure of local governance, and some had a character of Gozoku like TAIRA no Masakado, in part of the initial stages, but were not treated as Gozoku in the meaning same as that in the ancient history.
However, in the general use of Gozoku as the meaning of 'a potent clan' or 'powerful clan' (for example the use like 'Gozoku in △△ District, OO Province' in the period of the Northern and Southern Courts), the term "Gozoku" was often used to describe Jito (manager and lord of manor), Akuto (a villain in the medieval times), and samurai families at the same level as daimyo in the feudal lord class from Kokujin (local samurai) in the subsequent periods, and they were sometimes described as Gozoku until the Sengoku Period (Period of Warring States) and the Azuchi-Momoyama period.