Julius Caesar is famous for describing hugely complicated strategic problems, then adding his famous Vini, vidi, vici: 'I came, I saw, I conquered'. But what did his strategic genius consist of? And how did he justify extending the Roman Empire right across Western Europe?

Did Rome acquire her empire, not quite in a fit of absent-mindedness, but defensively, or was she ruthlessly expansionist? Gaius Iulius Caesar's account of his Gallic Wars (58-50 BC) explained his military operations as 'just' wars: Rome came to the rescue of allies and quelled lawless rebels. Admittedly, Caesar showed outstanding generalship. Forced marches by Roman infantry, operations - even in winter - caught adversaries by surprise. Complementing kinetic tools of siege craft and battle, Caesar's diplomacy turned Gallic and Germanic tribes and their leaders against each other, forging alliances and isolating adversaries, just as he had done previously in Roman domestic politics.

Dr Louis Rawlings helps us dissect Caesar as a strategist and as a political animal. Rawlings holds his degrees from University College London, having previously taught there and at the Department of War Studies, King's College London. He is now Senior Lecturer in Ancient History at Cardiff University.