This edition is of Book I of Lucan's epic poem, De Bello Civili, sometimes also known as the Pharsalia, a great work of the Silver Age of Latin literature. Book I summarises the background to the civil war between Caesar and Pompey and takes the narrative as far as Caesar's crossing of the Rubicon and the outbreak of panic in the city of Rome, including many signs and portents. This edition includes an extensive introduction, the Latin text, notes on the text, critical apparatus and index.