This article traces the history of the greenbelt of Chandigarh, India’s first modernist city, designed by Le Corbusier. The zone’s protection was mandated by the Periphery Control Act of 1952, although the act’s contents are often misinterpreted and do not fully reflect the project team’s complex vision. This work clarifies the intentions behind the Periphery’s creation, and establishes its integration with the master plan. I demonstrate how ongoing transformations violate the spirit of the Periphery’s original purpose, but rarely the letter of the law. I highlight ongoing conflicts whose resolution will fundamentally shape the future of the Periphery and the master plan of Chandigarh.