modern Zhangye, Gansu). Juqu Nancheng put Jiankang under siege, but sent messengers to try to persuade Duan Ye that the Later Liang regime was becoming so corrupt as to be nearing destruction, and that with Duan's talents, he should be a leader. Duan Ye initially refused, but after 20 days of siege, no aid came from the Later Liang capital Guzang (姑臧, in modern Wuwei, Gansu). Duan Ye's advisors suggested that he accept Juqu Nancheng's proposal, and Duan Ye, who was also apprehensive of Lü Guang's officials Fang Gui () and Wang Xiang (), with whom he had inimical relationships, agreed. He took the title the Duke of Jiankang and changed era name, signifying a declaration of independence from Later Liang and the establishment of Northern Liang. He entrusted most important affairs of state to Juqu Nancheng. Reign Lü Guang's son Lü Zuan soon arrived and attacked Jiankang, but could not capture it. Soon thereafter, with the sorcerer Guo Nen () having rebelled at Guzang, Lü Zuan withdrew from Jiankang, allowing Duan Ye's nascent state to stand. In 398, Duan Ye sent Juqu Mengxun to attack Xi Commandery (), in modern Zhangye, Gansu), and Juqu Mengxun captured it and its governor, Lü Guang's nephew Lü Chun (). Soon thereafter, Jiuquan (酒泉, roughly modern Jiuquan, Gansu) and Dunhuang (敦煌, roughly modern Dunhuang, Gansu) Commanderies submitted as well, allowing Northern Liang to take over a large portion of formerly Later Liang territory. Lü Guang's son Lü Hong () then also withdrew from Zhangye (張掖, in modern Zhangye), and Duan Ye moved his capital from Jiankang to Zhangye to further pressure Later Liang. He trailed Lü Hong to try to attack him, against Juqu Mengxun's advice not to cut off Lü Hong's escape, and was defeated by Lü Hong, saved from destruction only by Juqu Mengxun. In 399, Duan Ye claimed the title of Prince of Liang. He made Juqu Mengxun and Liang Zhongyong () key ministers. In summer 399, Lü Zuan and Lü Guang's heir apparent Lü Shao jointly attacked Northern Liang. Duan Ye sought aid from Southern Liang's prince Tufa Wugu, and Tufa Wugu sent his brother Tufa Lilugu and the general Yang Gui () to assist him. Duan Ye, because of the Southern Liang aid, was set to make a counterattack against Later Liang forces, but Juqu Mengxun persuaded him that doing so would give Southern Liang an opening to