Over the past three millennia, China has spent at least eleven centuries at war. The Roman Empire was in conflict during at least half of its lifetime. Since 1776, the US has spent over one hundred years at war. If the dream of peace has been universal throughout the history of humanity, why have we so rarely been able to achieve it? In this sweeping book, Jonathan Holslag has produced a new history of the world, from the Iron Age to the present, that investigates the various causes of conflict between empires, nations and peoples, and the impact of diplomacy and cosmopolitanism. A birds-eye view of three thousand years of history, the book investigates the balance of war and peace from Ancient Egypt to the Han Dynasty, the PaxRomana to the rise of Islam, the first ancient peace conferences to the creation of the United Nations. In an era of growing geopolitical tensions, A Political History of the World shows how we got to where we are- and why we should never take peace for granted.