Northeast Flag Replacement

The Northeast Flag Replacement (traditional Chinese: 東北易幟; simplified Chinese: 东北易帜; pinyin: Dōngběi Yìzhì) refers to Zhang Xueliang's announcement on 29 December 1928 that all banners of the Beiyang government in Manchuria would be replaced with the flag of the Nationalist government, marking the end of the Northern Expedition, thus nominally uniting China under one government. == Background == In April 1928, Chiang Kai-shek was reinstated as commander of the National Revolutionary Army, the position he previously resigned from after taking responsibility for splitting the KMT during the First Northern Expedition.

Source: Wikipedia — Northeast Flag Replacement (CC BY-SA 4.0)