Guo Ziyi is depicted in the Wu Shuang Pu (無雙譜, Table of Peerless Heroes) by Jin Guliang.

Around 735 Guo Ziyi was saved from a court martial by the poet Li Bai, who intervened on his behalf with the local commander.

[2] Unlike other members of his family, Guo Ziyi entered political life through the official military examinations instead of a literary exam (for civil servants).

When rebellion broke out in 755, Guo Ziyi was assigned to protect the Tong Pass, a strategic location on the Chinese frontier.

The rebels saw little to loot and were discouraged, while the Tang troops were prepared to fight, motivated by the desire to protect their families in the Tong Pass and the capital of Chang'an.

Guo engaged the seven thousand troops at the Battle of Qingbi and scattered the rest while suffering few casualties to his own force, winning his first victory.

Members of the entourage, including the troops, resented Yang Guozhong, holding him responsible for the failed strategy that led to the fall of Chang'an.

Meanwhile, Guo Ziyi confronted a great force of a hundred thousand led by rebel commander Shi Siming.

Guo was given the post of Imperial Commander and Suzong provided support for his military operations, which were met with great success.

The rebels suffered dramatic losses, including the deaths of their generals, after which Guo declared victory on the Shaanxi front.

This became a disaster, but Guo Ziyi managed to make the best out of the situation by convincing his fellow jiedushi that they could have one easy victory if they laid siege to the rebel city.

The Tibetans, confused by these actions, panicked, scattering when the rumor spread that Guo Ziyi moved against them with a large force.

Many Chinese military historians consider this victory to be the best example of Sun Tzu's idea of the cleanest kind of battle, "a war with no loss on either side but simply played out with the desired effect for the victor."

Nevertheless, the Tibetan army retreated, and when Guo Ziyi arrived at Chang'an with his "large" force, Daizong appeared to him and stated, "By employing the Elder not sooner: so many deaths reached, woe is this!"

The Tibetans attacked again in 765, when the Tiele jiedushi Pugu Huai'en sent false messages to Trisong Detsen, the emperor of Tibet, stating that Guo Ziyi had died.

The Tibetan emperor was eager to avenge his earlier defeats, and dispatched a large force to attack Tang China again.

When news of the Tibetan attack reached Emperor Daizong, he dispatched Guo Ziyi to defend the Tang with only few thousand men.

His officers and son Guo Xi (郭晞) were so dismayed and panicked by his intention that they would not let go of his horse's reins, declaring such an act would be suicide.

The Uyghur chieftains, many of whom had joined the rebel side in the An Lushan Rebellion, were surprised and panicked to hear that Guo was alive, deciding that they had to meet with him.

He lived to the age of 85 (by East Asian reckoning) and was given the posthumous name of Zhongwu (忠武: "Loyal and Martial") after his death.

Guo was so angry at his son for implying such an idea of disloyalty that he had him locked up and waited for Emperor Daizong to pass judgement on him.

As a reward, the Jade Emperor had Guo guided to heaven and bestowed the Celestial post of "God of Prosperity and Happiness" to him.

Guo Ziyi has been credited by many historians with putting down the An Lushan Rebellion, characterizing him as the man who single-handedly saved the Tang dynasty.

His impact on East Asia was also dramatic in that he renewed Tang relations with many of its Uyghur allies, who later supported the dynasty in campaigns against the Tibetan Empire.

In the event, Suzong commuted Li Bai's sentence to exile, and later pardoned him, and Guo Ziyi was allowed to retain his rank.