but did not carry out any military action. Second Mongol mission (1273) At Beijing, Kublai Khan, who was preparing an invasion of Japan, decided against a war with Pagan—for the time being. On 3 March 1273, he sent a 4-member delegation led by an imperial ambassador, the First Secretary to the Board Rites, to Pagan. The delegation carried a letter from the emperor. The letter says: "If you have finally decided to fulfill your duties towards the All-Highest, send one of your brothers or senior ministers, to show men that all the world is linked with Us, and enter into a perpetual alliance. This will add to your reputation, and be in your own interests; for if it comes to war, who will be the victor? Ponder well, O king, Our words." This time, the Burmese king received the imperial envoys but still refused to submit. The Burmese chronicles say that the king was so insulted that he had the envoys executed. But both Burmese inscriptional evidence and Yuan records indicate that the envoys were not executed. At any rate, the imperial envoys did not get back to Yunnan in due time. The newly formed Yunnan government sent another delegation to investigate the whereabouts of the delegation, but the delegation could not reach Pagan because of an ongoing rebellion en route. Mongol consolidation of borderlands (1275–1276) Meanwhile, in 1274, the former Dali Kingdom was officially reorganized as the Province of Yunnan, with Sayyid Ajjal Shams al-Din Omar as governor. In May 1275, the governor sent a report to the emperor stating that the embassy had not returned; that the Burmese evidently had no intention of submitting; and that war was the only way forward. But the emperor rejected an outright invasion. Just coming off a disastrous Japanese campaign, the emperor was unwilling to commit the central government troops to what he considered a low priority affair. He was now focused on delivering the final blow against the Song; the emperor ordered the Yunnan provincial army to secure the borderlands in order to block the escape path of the Song refugees. He also sanctioned a limited border war if Pagan contested the takeover. As planned, the Yunnan army proceeded to consolidate the borderlands in 1275–76. Elsewhere, the main Mongol armies had captured most of the Song territory by 1276. By 1277, at least one Burmese vassal state named "Gold Teeth" (modern