The 3rd successor to the throne of the Second Sho Dynasty was Sho Shin. His reign left behind some of the most exceptional achievements of the dynasty. He was king during what is called the Golden Age of the Ryukyu Kingdom.
After the death of King Sho En, the king's brother succeeded him but abdicated after a reign of less than 6 months after which Sho Shin became king at the young age of 12. During Sho Shin's long 50-year reign he was gradually able to build up a centralized government with the king in power.
One of the first reforms he carried out was requiring the local regional chieftains, known as Aji, to reside in the capital Shuri and set up a political bureaucracy to manage rule over the regions. Furthermore, he ordered the establishment of a class system that could be instantly recognizable by the color and materials of the hats (Hachimachi) and ornamental hairpins (Kanzashi) worn by the Aji.
Sho Shin also partitioned the islands, municipalities, and sections of the villages and towns into the jurisdictions currently in use in Okinawa. The sphere of the administration also included the Amami and Miyako Islands.
Sho Shin's reign also saw the systematization of the priestesses (Noro) with a supreme high priestess called the Kikoe Ogimi. This system was intended to exercise a spiritual control over the power of the court.
With the financial resources gained through intermediary trading, Sho Shin instituted many engineering projects throughout the kingdom.
All of these accomplishments helped to establish a centralized state and a period with a prosperity that can be appropriately called "The Golden Age of the Ryukyus."

Letter from the Ming Emperor Xiao Zong to the Ryukyu Kingdom's King Sho Shin

Warrant of appointment issued to the Shuri-Ufuyaku of Nakada on Iheya-jima Island

Warrant of appointment issued to the Noro priestess of Yaga in Haneji Village