Indonesia
The Javanese kingdom of Majapahit, which dominated eastern Java in the 14th and 15th centuries, was divided into nagara (provinces). The administration of these nagara was entrusted to members of the royal family, who bore the title of Bhre i. e. Bhra i, "lord of" (the word bhra being akin to the Thai Phra), followed by the name of the land they were entrusted with: for example a sister of king Hayam Wuruk (r. 1350-1389) was "Bhre Lasem", "lady of Lasem". This system was similar to the Apanage system in Western Europe.
Sultan Agung, king of Mataram in Central Java (r. 1613-1645), would entrust the administration of territories he gradually conquered all over the island of Java, to officials bearing the title of Adipati, this title is hereditary. Such territories were called Kadipaten.
The VOC (Dutch East Indies Company), while gradually taking control of Javanese territory, would maintain the existing Mataram administrative structure. Adipati were called "regenten" in Dutch, and the territories they administered, "regentschappen".
In the 19th century, the Javanese term for regent was bupati. French traveller Gérard Louis Domeny de Rienzi mentions bapati.
The bupati have been maintained in the modern Indonesian administrative subdivision structure, heading a kabupaten, the subdivision of a provinsi or province.
The word Adipati is still found in the official title of the hereditary dukes Mangkunegara of Surakarta and Paku Alam of Yogyakarta i. e. Kanjeng Gusti Pangeran Adipati Arya (shortened into KGPAA).
Read more about this topic: Duke, Equivalents