Early life

Yang Hong was from Wuyang County (武陽), Qianwei Commandery (犍為), which is located within present-day Pengshan, Sichuan. When Liu Zhang was the governor of the Yi Province, he served successively in several commanderies. After Liu Bei successfully conquered Yi province, Li Yan recommended him as an Officer of Merit (功曹). Later, Li Yan wished to relocate the Administrator's headquarters, however Yang Hong firmly opposed this decision and in the end his opinion was ignored. Following this, he resigned from his position as an Officer of Merit. However, Li Yan still recommended Yang Hong to the Prefectural capital as an official.

Service under Liu Bei

Afterward, when Liu Bei battling Xiahou Yuan at Hanzhong, he sends requests for reinforcement to be sent. At this time, Zhuge Liang was in charge of the approvisionnement and asked Yang Hong's opinion about this. Yang Hong told him: Zhuge Liang agreed with Yang Hong's opinion.

At the same moment, the Administrator of Shu Commandery (蜀郡太守), Fa Zheng was helping Liu Bei in the north. Zhuge Liang sends a memorial to have Yang Hong take the vacant position, he quickly adapted and the many problems were soon all resolved therefore he was given the formal appointment. Soon he was relocated to another office in Yi province.

After Liu Bei proclaimed himself emperor, he launched a campaign against Wu but was unsuccessful and retreated to Yongan. At this time, the Administrator of Hanjia Huang Yuan (黃元) had a bad relationship with Zhuge Liang and fearing that after Liu Bei's death would have problems led a rebellion in his commandery, he burned down the city of Linqiong. During this Zhuge Liang had left to examine the condition of Liu Bei therefore Chengdu was weak and badly defended, Huang Yuan was all the more excessive and fearless in his attitude. Yang Hong at once informed Liu Chan to dispatch their own personal troops along with the Generals Chen Hu (陳曶) and Zheng Chuo (鄭綽) to suppress Huang Yuan's rebellion.

Everyone was afraid that if Huang Yuan failed to conquer Chengdu, he would try to occupy Hanzhong from Yuexi. However, Yang Hong said: And indeed, Yang Hong's prediction was true and Huang Yuan was taken alive. After this, he was enfeoffed as a Secondary Marquis (關內侯), resumed his occupation as Administrator of Shu Commandery and given the rank of General of Loyalty and Integrity (越騎校尉) and later became Lieutenant Cavalry of Yueqi (越騎校尉).

Service under Liu Shan

In 227, Zhuge Liang moved to the north and made his headquarters in Hanzhong, wanted to employ Zhang Yi in his office as his Chief Clerk (長史) and asked Yang Hong's opinion about this. Yang Hong told him: When young, Yang Hong and Zhang Yi were close friend however when Zhang Yi was in exile in Wu and Yang Hong temporarily took charge of his commandery. He didn't give special treatment to his son Zhang Yu, who was a minor official when he committed a small offence. When Zhang Yi came back to Shu, he heard about this and was resentful of Yang Hong, from this moment their relation deteriorated.

Later, when Yang Hong saw that Zhuge Liang was raising troops. He personally visited Zhang Yi and told him what he advised Zhuge Liang about him. Zhang Yi answered that Zhuge Liang already appointed him and that he couldn't prevail this. People were thinking that Yang Hong's intention was to be chief clerk at the place of Zhang Yi or that knowing Zhang Yi was resentful of him, Yang Hong didn't want for him to occupy a critical position and manage important matters. However, when in position, Zhang Yi had conflict with the Colonel (校尉) Chen Shu (岑述) until their relation reached hatred and anger. Zhuge Liang knew about this and send a letter to Zhang Yi where he reprimand him for not putting the interest of the State before his personal relation. Because of this event, the people understood that Yang Hong was truthful in his statement.

Appraisal

When Yang Hong was young, he didn't enjoy scholarship, but he was a faithful and altruistic man. He was concerned about the wellbeing of others as if they were his own family and was known to treat his stepmother with utmost filial piety. He died while serving in office in 228. At first, Yang Hong served under Li Yan but due to personal opinions, he retired however while Li Yan was still serving as Administrator of Qianwei, Yang Hong had been already relocated as Administrator of Shu Commandery. At this time, he was helped by He Zhi, who served under him as a personal Aide Officer. He Zhi was talented, cunning, made numerous accomplishments and was soon promoted to the role of Prefect. Several years later, he was promoted again to be the Administrator of Guanghan. At the same time, Yang Hong was still serving as the Administrator of Shu Commandery. Because of this, all the people in the west admired Zhuge Liang for his ability to thoroughly employ the men of great talent.

生平

楊洪在劉璋任益州牧時曾到多個郡任職，劉備奪益州後，犍為太守李嚴任命楊洪為功曹。後來因李嚴意欲搬遷犍為郡的治所，不顧楊洪極力反對，楊洪於是辭任功曹。李嚴於是推薦楊洪當蜀部從事。劉備爭奪漢中時大力支持出兵奪取漢中以保持益州安定，得到諸葛亮賞識而表楊洪領蜀郡太守，任內盡力辦公，因此被升為蜀郡太守。不久轉任益州治中從事。

劉備稱帝後，便出兵征討東吳，發動夷陵之戰，但最終被擊敗，退到永安。

漢嘉太守黃元聽聞劉備患病，而自己向來和諸葛亮不和，害怕一旦劉備逝世，諸葛亮當權後會遭到報復，於是趁成都空虛叛亂，縱火燒臨邛，楊洪於是派將軍陳曶和鄭綽討伐黃元，當時眾人都認為黃元戰敗後會逃到南中固守，但楊洪認為黃元不會這樣，必會沿江東下逃走，派陳曶等在南安峽口阻截，最後果然生擒黃元。建興元年（223年），賜爵關內侯，再次被任命為蜀郡太守、忠節將軍，後來擔任越騎校尉，繼續治理蜀郡。

楊洪不好學問，但他忠心事朝，對公事如同家事般緊張，建興六年（228年）在任內逝世。

三國演義

在65回，楊洪隨劉璋投降。在80回提及楊洪是治中，91回提及孔明任命楊洪為尚書。但三國志只提及楊洪做過治中，沒有說他做過尚書。