Shō Hashi
Although the history books agree that Shō Hashi unified Okinawa, the accounts of the unification process contain non-negligible inconsistencies. The oldest "Chūzan Seikan" states that after Shō Hashi succeeded his father Shō Shishō as Sashiki Aji in 1402, he overthrew the King of Nanzan and claimed the title. He then overthrew the Chūzan King Bunei in 1421 to become the King of Chūzan. He finally killed the King of Hokuzan in 1422. Sai Taku's edition of "Chūzan Seifu" generally follows the "Chūzan Seikan". However, it dates Shō Hashi's conquest of Chūzan 16 years earlier than the "Chūzan Seikan". It also claims that Shō Hashi installed his father Shō Shishō as King of Chūzan instead of himself. Shō Hashi became the King of Chūzan only after Shō Shishō's death in 1421. Sai On's edition of "Chūzan Seifu" is drastically different from these two books. It claims that Shō Hashi defeated the Chūzan King and installed his father Shō Shishō in 1406. He conquered Hokuzan in 1416 and Nanzan in 1429.