Under the reign of King Zhuang, Chu reached the height of its power and its ruler was considered one of the five Hegemons of the era. After a number of battles with neighboring states, sometime between 695 and 689 BCE, the Chu capital moved south-east from Danyang to Ying. Chu first consolidated its power by absorbing other states in its original area (modern Hubei), then it expanded into the north towards the North China Plain. In the summer of 648 BCE, the State of Huang was annexed by the state of Chu. The threat from Chu resulted in multiple northern alliances under the leadership of Jin. These alliances kept Chu in check, and the Chu kingdom lost their first major battle at the Chengpu in 632 BCE. During the 6th century BCE, Jin and Chu fought numerous battles over the hegemony of central plain. In 597 BCE, Jin was defeated by Chu in the battle of Bi, causing Jin's temporary inability to counter Chu's expansion. Chu strategically used the state of Zheng as its representative in the central plain area, through the means of intimidation and threats, Chu forced Zheng to ally with itself. On the other hand, Jin had to balance out Chu's influence by repeatedly allying with Lu, Wey, and Song. The tension between Chu and Jin did not loosen until the year of 579 BCE when a truce was signed between the two states. At the beginning of the sixth century BCE, Jin strengthened the state of Wu near the Yangtze delta to act as a counterweight against Chu. Wu defeated Qi and then invaded Chu in 506 BCE. Following the Battle of Boju, it occupied Chu's capital at Ying, forcing King Zhao to flee to his allies in Yun and "Sui". King Zhao eventually returned to Ying but, after another attack from Wu in 504 BCE, he temporarily moved the capital into the territory of the former state of Ruo. Chu began to strengthen Yue in modern Zhejiang to serve as allies against Wu. Yue was initially subjugated by King Fuchai of Wu until he released their king Goujian, who took revenge for his former captivity by crushing and completely annexing Wu. Warring States period Freed from its difficulties with Wu, Chu annexed Chen in 479 BCE and overran Cai to the north in 447 BCE. By the end of the 5th century BCE, the Chu