Urban expansion is a global phenomenon during which many common spaces, often with complex histories of governance and stewardships become redefined within prevailing notions of urbanity. However, such commons often pose challenges that result in conflict with respect to their use, management, and ownership. In this paper, we use the example of a lake in the South Indian megapolis of Bengaluru (formerly Bangalore) to look at different changing notions of urban commons pictured against a backdrop of rapid urbanization, migration, and landscape change. We look at conflicts at each period of change and argue that many of these have shaped the landscape of today and perhaps may be responsible for current notions of ownership associated with the landscape. We combine landscape change analysis through geospatial means along with official archival records, oral narratives, and secondary information sources to describe gradual loss of an urban commons. We then pose that knowledge of historical contexts of access to ecosystem services, exclusion, conflict, and the mechanisms of conflict resolution around urban commons can help understand trends in contemporary management of commons. This knowledge would help shape more equitable and ecologically robust policy frameworks that govern these vulnerable resources.