Zhong Yao, an advisor of Cao Cao, suggests an invasion of Zhang Lu's territory in the year 211.

However, Ma Chao and Han Sui, whose territory is between Cao Cao's and Zhang Lu's, interpret the massing of forces as an attempt to invade their own lands.

They rebel against Cao Cao, and after much fighting, Cao Cao's forces are victorious.

However, they are in no shape to continue the invasion to Hanzhong.

Ma Chao retreats to Hanzhong and pledges allegiance to Zhang Lu, who considers marrying his daughter to him.

However, a servant of Zhang Lu's, Yang Bo, says, "A man like that, who has no love for even his parents (referring to the execution of Ma Teng caused by Ma Chao's rebellion), cannot love another" and the marriage proposal is scrapped.

Ma Chao then borrows soldiers from Zhang Lu and attempts to regain some of his lost territory from Cao Cao, but is ultimately unsuccessful.

His failures cause the relationship between the two to sour.

When Liu Bei's forces surround Liu Zhang, Ma Chao chooses this time to take his leave of Hanzhong, and with his personal army he joins Liu Bei.

Ma Chao's subordinate Pang De, however, remains in Zhang Lu's service.

Cao Cao again launches a campaign to conquer Hanzhong in 215.

Initially, Zhang Lu has no hope of standing against Cao Cao's armies, and plans to surrender.

His younger brother Zhang Wei, however, insists on fighting and leads his army against the invading forces.

He is soon killed in battle, and again Zhang Lu considers surrendering.

His advisor Yan Pu tells him that in surrendering so readily, they would have no position to negotiate from.

Instead, Zhang Lu retreats to his fortress at Bazhong.

When leaving his capital, he does not destroy his wealth and treasures, nor attempt to take them with him, instead leaving them behind saying "These things belong to the country, not to me."

Cao Cao is greatly impressed by this, and sends a messenger to Zhang Lu asking him to surrender.

Yan Pu's plan is successful, as Zhang Lu and his forces are warmly welcomed by Cao Cao.

He is given the title General who Suppresses the South and his five sons are granted the rank of marquis.

He marries his daughter to a younger son of Cao Cao, Cao Yu.

As further demonstration of the bad blood between Zhang Lu and Ma Chao, when Cao Cao turns Ma Chao's son Ma Qiu over to Zhang Lu, he immediately executes him.

Following Cao Cao’s defeat of Zhang Lu and subsequent seizure of Hanzhong, Sima Yi and Liu Ye advise him to take advantage of the victory to attack Yi Province, since it is still unstable under Liu Bei's new government and Liu himself is away in Jing Province.

Cao Cao refuses and leaves Xiahou Yuan, Zhang He and Xu Huang to defend Hanzhong.

Zhang Lu, who dies not long after surrendering to Cao Cao, is created a marquess.

The Five Pecks of Rice religion is continued by his sons, eventually to evolve under the Tang Dynasty into the Taoist religion known as Zhengyi Dao, or the Way of Complete Orthodoxy.