He, perhaps inadvertently, did introduce a key reform, which turned out to be the most important and most enduring of his legacies. It was his policy to administer the Shan states, which had constantly raided Upper Burma since the late 13th century. The king permitted the "saophas" of the states to retain their royal regalia and ceremonies, and feudal rights over their subjects. The office of the saopha remained hereditary. But the incumbent "saopha" could now be removed by the king for gross misconduct although the king's choice of successor was limited to members of the saopha's own family. The key innovation was that he required sons of his vassal rulers to reside in his palace as pages, who served a dual purpose: they were hostages for good conduct of their fathers and they received valuable training in Burmese court life. His Shan policy was followed by all Burmese kings right up to the final fall of the kingdom to the British in 1885.