The Longest Day in Chang'an

Chang'an, the ancient urban heart of the empire, is suddenly gripped by a looming threat. A mysterious army closes in and the city braces for action as word spreads of an attack within one day. As panic ripples through the corridors of power and the streets fill with rumors, the elites scramble to shelter themselves while the city’s guardians struggle to organize a response. In the midst of this crisis an infamous figure from the underworld emerges not to profit from the chaos but to help avert disaster, complicating loyalties and forcing the city's rulers to reassess who can be trusted. With time running out danger and deception collide in a race to save Chang'an.

Directed by Cao Dun and adapted from Ma Boyong's novel, the series premiered in 2019. It blends crisp plotting with lavish Tang era visuals and a large cast, delivering tension through well choreographed action and practical effects.

The show sparked renewed interest in Tang era intrigue, inspiring online discussions about the line between law and crime and prompting a wave of fan art and historical interest. It also influenced small screen fashion and sparked online fan theories.

Critics praised the show for tight pacing, strong performances by Lei Jiayin and Jackson Yee, and its atmospheric recreation of a bustling Tang capital. The series foregrounds duty versus personal risk, loyalty, and the pressure of time, delivering suspense without sacrificing historical texture.

Awards The series drew attention from major Chinese awards, earning nominations that highlighted its production design, period accuracy and standout performances. Critics praised Cao Dun's direction and the way the story builds tension while preserving the historical texture.