Chadwick (1998) also reports Yi's (1996) study of the history of such screens. He attempts to establish whether they were used at the start of the Joseon Dynasty reigned by King Taejo (r. 1392–1398). One suggestion Yi reports is that the practice of using the Five Peaks screen was established by Jeong Do-jeon. He was instrumental in the adoption of Neo-Confucianism as the Joseon's state ideology. Jeong Do-jeon used the screen as an important part of the design of the Joseon palace architecture in 1392. However, there is a painting from the 16th century referred to as "The martial arts performance at Soch'ong-dae in the reign of King Myeongjong" (r. 1545–1567) and there is no screen behind the throne. A 19th century copy however has the screen in place behind the throne. Yi therefore suggests that the 1392 date might be far too early and prefers a more recent date for the establishment of the screens. He suggests that screens role might well have been adopted after the 1592 Imjin wars as an attempt to reaffirm the dynasty's power.