The Java War (Javanese: ꦥꦼꦫꦁꦗꦮ; Dutch: De Java-oorlog; Indonesian: Perang Jawa), also known in Indonesia as the Diponegoro War (Javanese: ꦥꦼꦫꦁꦢꦶꦥꦤꦼꦒꦫ; Indonesian: Perang Diponegoro), was an armed conflict in central and eastern Java from 1825 to 1830, between native Javanese rebels headed by Prince Diponegoro and the Dutch East Indies supported by Javanese princely states. It is considered a watershed in Javanese history, culture, and society.
During the early nineteenth century, declining Dutch power along with increased centralization of colonial authorities through brief French and British controls had changed the political order established after the 1755 Treaty of Giyanti, at the expense of the native Javanese princely states. After the deaths of Sultans of Yogyakarta Hamengkubuwono III and IV, along with the return of Dutch presence, Hamengkubuwono III's eldest son Diponegoro became estranged from Yogyakarta's regency of Hamengkubuwono V and with the colonial government. With a millenarian movement emerging and claimed visions of a holy war, Diponegoro would launch his rebellion following tensions caused by a government road project in July 1825.