Hedley Bull was an influential Australian scholar in the field of international relations. Born in 1932, he is best known for his work on the nature of international order and the role of states in the global system. His most notable book, The Anarchical Society, published in 1977, explores how states coexist in an international system characterized by anarchy. Bull was a key figure in the English School of international relations, which emphasizes the importance of international norms and institutions. He served as a professor at Oxford University and contributed significantly to debates on global governance, diplomacy, and the balance of power among nations.