One year ago, Hong Kong Polytechnic University was in flames.

Police and student protesters faced off at the campus — one of the Hong Kong’s best-known — in a chaotic 16-day siege last November that became a symbol of the battle between the city’s China-backed administration and anti-government protesters.

Today, what had once been a bustling, freely accessible campus is locked down, its protest movement extinguished in a series of aggressive moves to stifle dissent in the Asian financial hub.