New research published in Environmental History Review provides the first direct climate evidence for the destabilization of the Sena Dynasty in medieval Bengal. By analyzing the growth rings of 800-year-old submerged mangrove stumps discovered in the Sundarbans, scientists identified a 40-year period of extreme monsoon volatility starting around 1160 CE. This era was characterized by unpredictable cycles of devastating floods followed by severe drought.
The study suggests that these environmental stressors severely impacted the agrarian economy of the delta, leading to widespread famine and the eventual collapse of central administrative control. This climate-archaeology breakthrough highlights how the highly specialized hydraulic infrastructure of the Sena rulers was unable to cope with rapid shifts in rainfall patterns. The findings offer a sobering historical parallel for the modern delta's vulnerability to climate change.