Yixin played a significant role in resolving the crises of the Second Opium War and the Taiping Rebellion, and he actively promoted modernization, which led to a brief period of political stability and revitalization for the Qing government.

[5] Yixin was mentored by Zhuo Bingtian (卓秉恬) and Jia Zhen (賈楨), two eminent scholar-officials who obtained the position of jinshi (進士; successful candidate) in the imperial examination in 1802 and 1826 respectively.

[6][7] In 1850, when the Daoguang Emperor became critically ill, he summoned Zaiquan (載銓), Zaiyuan, Duanhua, Sengge Rinchen, Mujangga, He Rulin (何汝霖), Chen Fu'en (陳孚恩) and Ji Zhichang (季芝昌) to Shende Hall (慎德堂) in the Old Summer Palace, where he revealed to them a secret edict he wrote previously.

In accordance with their father's secret edict, the newly enthroned Xianfeng Emperor granted Yixin the title "Prince Gong of the First Rank" (恭親王) in the same year.

In 1851, the Xianfeng Emperor established an office for Prince Gong, gave him permission to enter the inner imperial court, assigned him to be in charge of patrol and defence matters, and ordered him to continue carrying the White Rainbow Sword given to him by their father.

[9] In October 1853, as the Taiping rebels closed in on Jinan (畿南; the area south of the Hai River), Prince Gong was appointed to the Grand Council, which was in charge of military affairs.

[12] Prince Gong moved to Changxindian (長辛店; in present-day Fengtai District, Beijing) and called for an assembly of the troops stationed there to enforce greater discipline and raise their morale.

[13] On 24 October 1860, Prince Gong concluded the negotiations with British, French and Russian officials, signing the Convention of Peking on behalf of the Qing dynasty.

[14] In 1861, Prince Gong set up the Zongli Yamen, which functioned as the Qing government's de facto foreign affairs ministry, and placed Guiliang (桂良) and Wenxiang in charge of it.

The generals Shengbao (勝保), Jingchun (景淳) and others were ordered to oversee training of Qing troops stationed in Beijing and northeast China.

[15] Before the Xianfeng Emperor died in August 1861 in the Chengde Mountain Resort, he appointed a group of eight regents – led by Zaiyuan, Duanhua and Sushun – to assist his underage son and successor, Zaichun.

Prince Gong firmly declined to accept the "iron-cap" privilege, and instead sought to be concurrently appointed as zongling (宗令; Head of the Imperial Clan Court) and put in charge of the Shenjiying (a firearms-equipped unit in the Qing army).

[18] In 1864, Qing forces finally suppressed the Taiping Rebellion after a war lasting more than a decade, and recaptured Jiangning (江寧; in present-day Nanjing) from the rebels.

The imperial court issued a decree to praise Prince Gong for his effective leadership in the regency that led to the end of the rebellion – in addition to conferring more prestigious titles on his sons Zaicheng, Zaijun and Zaiying.

[19] As the longstanding leader of the Zongli Yamen, which he established in 1861, Prince Gong was responsible for spearheading various reforms in the early stages of the Self-Strengthening Movement, a series of measures and policy changes implemented by the Qing government with the aim of modernising China.

[citation needed] Around April 1865, an official, Cai Shouqi (蔡壽祺), accused Prince Gong of "monopolising state power, accepting bribes, practising favouritism, behaving arrogantly, and showing disrespect towards the Emperor".

Although the empress dowagers did not restore Prince Gong as Prince-Regent, they permitted him to remain in the inner imperial court and continue running the Zongli Yamen.

"[20] In March 1868, as the Nian rebels approached the suburbs of Beijing, Prince Gong was tasked with mobilising troops and managing defence arrangements.

[21] In 1869, An Dehai, a court eunuch and close aide of Empress Dowager Cixi, was arrested and executed in Shandong Province by Ding Baozhen, the provincial governor.

[citation needed] In October 1872, when the Tongzhi Emperor married the Jiashun Empress, he granted Prince Gong the "iron-cap" privilege again.

Towards the end of the year, the Tongzhi Emperor increased Prince Gong's salary by more than twice that of a normal qinwang, but died not long later in around December.

As a consequence, Empress Dowager Cixi reprimanded Prince Gong and his colleagues for their dispirited and indecisive attitude towards the war, and removed them from their positions.

Some officials such as Baojun (寶鋆), Li Hongzao, Jinglian (景廉) and Weng Tonghe, who previously served in Prince Gong's administration, were also dismissed from office.

Although Prince Gong had been recalled to politics, Empress Dowager Cixi also decreed that since he had not yet recovered from illness, he was exempted from having to constantly attend court sessions.