[2] Deeply favoured by Empress Dowager Cixi, he served in a number of important civil and military positions in the Qing government, including the Zongli Yamen, Grand Council, Grand Secretary, Viceroy of Zhili, Beiyang Trade Minister, Secretary of Defence, Nine Gates Infantry Commander, and Wuwei Corps Commander.

Ronglu was a yinsheng (蔭生), a type of position awarded to civil service candidates who successfully gained admission to the Guozijian (Imperial Academy).

He started his career in the Ministry of Works as a yuanwailang (員外郎; assistant director) and was tasked with constructing roads in Zhili Province.

After the Qing and Japanese empires reached a peace settlement, Ronglu nominated Yuan Shikai to oversee the creation and training of the New Army.

Around the time, a group of officials led by Kang Youwei and Tan Sitong planned to carry out a series of reforms and get rid of conservative elements in the government.

Acting on the advice of Yang Chongyi (楊崇伊), Empress Dowager Cixi interfered in the situation and launched the 1898 Coup against the reformists.

Around the time, Empress Dowager Cixi had the intention of deposing the Guangxu Emperor and replacing him with Prince Duan's son Puzhuan (溥僎; 1875–1920).

Prince Duan and his followers continued to press the attacks against foreigners and kill any official in the imperial court who opposed them.

When Dong Fuxiang's Gansu Army was eager to attack the legations, Ronglu made sure that the siege was not pressed home.

[8] Ronglu had effectively derailed Prince Duan's efforts to capture the legations, and as a result, saved the foreigners inside.

The fourth decree ordered Ronglu to "send efficient troops of the Wuwei Corps swiftly, to the Beijing Legation Quarter, to protect all the diplomatic buildings.

Later that year, he supported the reforms proposed by Liu Kunyi and Zhang Zhidong in their memorial titled Jiang Chu Hui Zou Bian Fa San Zhe (江楚會奏變法三折).

Before Lady Yehenara (the future Empress Dowager Cixi) became a consort of the Xianfeng Emperor, Ronglu was allegedly in a romantic relationship with her.

The Empress Dowager always remembered Ronglu's support for her, even when they were young, and rewarded him by allowing his only surviving child, his daughter Youlan, to marry into the imperial clan.