The 'Ten Kings' at the Seikado Library, Japan, a most unusual and magnificent set of ten hanging scrolls replete with figural, landscape, flower, and decorative details, have been until now designated Important Artistic Properties by the Japanese government. Yet they have been admired without clear awareness of their provenance, likely patrons, function, and position in the evolution of Ten Kings paintings and East Asian painting at large.*br* Through the uncovering of pertinent archaeological and textual evidence, iconographic and stylistic analysis, and the reassessment of their place in the development of Ten Kings paintings in East Asia, this study will demonstrate that the 'Ten Kings' at Seikado, contrary to their present attribution to the Yuan dynasty (1286-1368), are instead most likely mid-Koryo dynasty (918-1392) paintings commissioned by the court. Comparative analysis to Koryo woodblock editions of the Ten Kings sutra in the Heainsa Repository and the Choson dynasty (1392-1910) depictions of the Ten Kings locate the Seikado set within the Ten Kings paintings tradition in Korea. Also, historical documentation on the architecture, ritual practice, and social customs in the Koryo court show great affinity corroborates the hypothesis that these paintings were likely commissioned by the Koryo royalty. In addition, formal comparisons to late Koryo paintings will suggest an earlier date than the 13th- and 14th-century Koryo Buddhist paintings known until now.*br* In the end, the Ten kings at Seikado fill an important gap in the history of Korean painting and also stand as significant and unique painting monuments in the history of East Asian art.