The Minister of Works (司空 Sīkōng) was one of the Three Excellencies and shared supreme ministerial rank with the Grand Commandant and the Minister over the Masses. His portfolio centred on public works and construction, and by extension aspects of infrastructure and state projects.
Role
The Minister of Works oversaw building projects, irrigation, and other large-scale works undertaken by the state. In the late Han and Three Kingdoms, the office was often filled by trusted officials or allies of the ruling faction. Holders might have little to do with actual construction; the title was above all a mark of rank and inclusion in the highest tier of the bureaucracy.
In the Three Kingdoms
Wei, Shu, and Wu all retained or adapted the title as part of their court structure, using it to reward officials and to maintain the appearance of continuity with Han precedent.