The Chancellor and the Regent

"Zai Zhi Tian Xia" (Governing the Realm) is a long-form historical time-travel novel by the web author cuslaa (real name Hu Changle, known online as "Godzilla"). It was serialized on Zongheng Chinese Network starting December 1, 2010, and concluded on February 4, 2019, totaling approximately 7.3 million characters. It is considered a representative work of the "knowledge-archaeology" style of Song dynasty time-travel fiction.

"Zai" refers to the chancellor and "zhi" to the executive minister: one who assists the sovereign above and brings peace to the common people below, before whom all officials yield, is the chancellor; one who aids in governance, sets national policy, and co-signs imperial edicts is the executive minister. The story opens with a plane crash: a young man of the present day, He Fang, crosses a thousand years to land in the Northern Song—a realm legendary for its "poverty and weakness" yet "more prosperous than the Han and Tang at their height"—and becomes Han Gang, a youth of humble birth. To preserve his modest share of happiness within a poor household, Han Gang rises step by step from a country scholar, relying on modern knowledge and a grasp of history's broader currents: he joins the campaign to open the He-Huang frontier, extending medical care and a military hospital system to the Guanzhong region and earning widespread renown; he passes the imperial examination and serves as magistrate of Baima County, settling refugees after a great drought; and his invention of the sled transports grain across the frozen Bian River, relieving famine in the capital. He later heads the Directorate of Armaments, driving improvements in craft and manufacture, and twice saves the day at moments of palace coup.

The novel takes the political landscape of the Xining era of the Northern Song as its framework, with historical figures such as Wang Anshi, Sima Guang, Su Shi, and Zhang Zai appearing in turn, unfolding layer by layer the conflict between the New Policies and the old laws, the external threats from the Liao and Western Xia, and the accumulated ills of the military and fiscal systems. Han Gang takes Zhang Zai's philosophy of qi as his substance and modern science as his application, seeking an alternative path for the empire through enlightenment and industry, until at last he finds his place among these historical figures—and takes upon his own shoulders the full weight of the title "chancellor and executive minister."