- "China is just a piece in the prize. We will rule the world, and the box you so kindly presented us, will be yet another tool to achieve a time of peace."
- ―Zhang Yong, elaborating on the Templars' goal of world control, 1532.[src]
Zhang Yong started as Liu Jin's right-hand man and was eventually initiated in the Order himself. Determined to usurp control over the Empire, he betrayed Liu Jin and staged him in an assassination attempt against the Zhengde Emperor. Yong succeeded, and Liu Jin was executed through the Ling Chi technique.
With the death of the Zhengde Emperor, he looked for a way to eradicate more prominent enemies and set up what was to be known as the Great Rites Controversy, purging the Chinese Assassins after the ascendance of the Jiajing Emperor which he also planned.
By 1529, Zhang Yong caught news of the Assassin Wang Yangming's spying and investigation about the Precursor box. He hunted Wang and found him in Nan'an, where Zhang killed the Chinese Mentor in a sword fight and reclaimed the box for himself. Spotting Shao Jun in the shadows, Zhang Yong ordered his guards to attack her as he escaped.
With the Tiger Qiu Ju, Zhang Yong discovered Shao Jun's former friendship and connections with the Empress Zhang, using her to draw the Assassin out by threatening her life; Jun took the bait and discovered the betrayal, but forgave her friend after knowing what was at stake. Qiu Ju then dueled Jun and Zhang Yong fled once more.
Later, in 1532, Zhang Yong planned to let Altan Khan and his Mongol Empire through the Great Wall of China – despite knowing the risk of barbarian invasion – to maintain his grip on power. Having confronted Zhang Yong on the Wall and subsequently chasing him across the landmark, Shao Jun assassinated him, ending his dangerous plans.
- In Chinese, Zhāng Yǒng's name is written as 張永.
- His surname, Zhāng (張) is a common Chinese family name that means "to open up, to stretch, to extend" and is also employed as the measure word for flat objects such as paper or cloth. However, its etymology is an allusion to archery as it originally referred to "stretching a bow". His personal name, Yǒng (永) means "eternity".