Interstate Relations in Northern India (800–1200 ce) is a critical analysis of the Empire and State, the RÀja-Maõçala, in medieval India. The book is an excellent interpretation of the composition of the state, the ancient Indian principles and categories of interstate relations dealing with rÀjya and maõçala (circle of states). This thoroughly researched work examines the state and its seven constituent elements (rÀjya). While avoiding the temptation of using Western categories and principles of international law, it provides an explanation of classification of states based on power, independence, tribute and political allegiance. In particular, it defines and analyses the ÈÀçguõya (sixfold policy of sandhi (peace), vigraha (war), yana (marching), Àsana (staying quite), dvaidhÁ-bhÀva (dual policy) and saڜraya (seeking shelter thereby correcting earlier misconceptions)). Furthermore, the theoretical formulations of circle of states and interstate relations between (800–1200 ce) have been placed in a historical context, and well attested by historical instances in north India. Based on geopolitics and power it demonstrates the impact of political thought on political expedients, stratagems and events, at a crucial time in Indian history. The influence of ideas on political behaviour of kings and trajectories and policies of kingdoms of the Candellas, PÀlas, ParamÀras, PratihÀras, RÀjpÂts, CÀÒukyas, RÀÈÇrakÂÇas, Arabs and CÀhamÀnas have been substantiated with facts and evidences. The author, Dr Shiva Gopal Bajpai, is to be congratulated for providing an accurate analysis of ancient Indian political theory and interpretation of its practical application by medieval rÀjÀs, thereby making a significant contribution to our understanding of Indian history.