["Tijdschrift voor Economische en Sociale Geografie, EarlyView. ", "\nUrban Planning Paralysis in Islamabad: Governance Conflicts and Uneven Urban Development (1959–2024). This graphical abstract presents a five‐panel framework examining institutional persistence in urban planning. (1) The master plan became locked‐in within concentric institutional layers of state authority, legal infrastructure, and property rights regimes. (2) A mixed‐methods design triangulates archival research, oral histories, legal‐institutional analysis, and spatial GIS. (3) Temporal dynamics across four periods reveal shifting coalitions, contested legal interpretations, and evolving land markets reinforcing path dependence. (4) Divergent urban outcomes emerge: formal sectors with socio‐economic privilege, informal zones of exclusion, and congested commercial hubs. (5) The synthesis model positions spatial arrangements at the nexus of political authority, legal frameworks, and economic relations—a triadic structure sustaining planning stasis despite episodic contestation.\n\nAbstract\nThis paper explains why Islamabad's master plan, intended for periodic revision, has remained in effect for six decades and how this permanence has shaped the city's sociospatial inequality. The analysis combines archival materials from the 1959 Yahya Khan Commission and Doxiadis Associates, Capital Development Authority files on review efforts (1972, 1986, 2005), court decisions, census indicators and published GIS evidence (1998–2023), and oral history interviews with officials. The findings show that comprehensive revision was repeatedly blocked not by inertia but by institutional lock‐in: zoning stability, judicialisation of planning and coalition resistance among state actors and land interests. These dynamics channelled growth into selective exceptions and managed informality, producing durable sociospatial differentiation in the region. This paper expands debates in economic and social geography on path dependence and urban governance in contemporary post‐colonial cities.\n"]