Around the beginning of the 14th century, when the Aji regional chieftains were struggling with each other for power on the main island of Okinawa, the outlying Sakishima Islands (Sakishima Island and the Miyako and Yaeyama Islands) began to develop agrarian villages in each of their regions. The village chiefs, called by various titles such as Tenta, Azu, and Kaara started to vie with each other for supremacy in struggles in a period termed the Age of the Rival Warlords or Gunyukakkyo.
On Miyako during the mid 14th century chieftains fought each other over who was to rule and the state of affairs deteriorated into confusion. The strongest of these warlords, named Meguro-muitui-miya, succeeded in unifying the island. However another powerful Aji, Yonaha-dutui-miya, pleged allegiance to King Satto on the main island of Okinawa in hopes of increasing his power. The result was that Miyako was divided into two powers.
In the middle part of the 15th century Meguro-muitui-miya's successor Nakasone-tuimiya, noted for his distinguished leadership, was appointed leader of the whole island of Miyako-jima in 1474 by King Sho En.
As Miyako-jima was unified, the neighboring Yaeyama Islands were engaged in violent struggles for hegemony even as they traded with each other.
Also, on islands such as Yonaguni and Iriomote, which were somewhat under the control of Miyako-jima Island, there was resistance to being controlled by either Miyako or Yaeyama. Finally, there was the Ryukyu Court which sought to rule them all. It was a period when complex military confrontations came to the surface.
Warrant of appointment issued to the Shuri-Ufuyaku of Miyako-jima Shimoji
