King Mahasena (273–301 CE) – Mahasena is a transformative figure whose 28-year reign combined massive hydraulic engineering with controversial religious politics. He constructed sixteen major reservoirs, including the colossal Minneriya tank, dramatically expanding irrigable land. However, his early alignment with Mahayana-leaning factions sparked conflict with orthodox Theravāda monasteries—he reportedly destroyed the Mahavihara monastery briefly before reconciliation. His reign illustrates the volatile intersection of sectarian politics, royal patronage, and infrastructural ambition. Despite controversy, his hydraulic legacy profoundly shaped Anuradhapura's agrarian base.