Memoria rerum gestorum (literally, ‘memory of deeds’) is yet another way of saying ‘history’, in the sense both of ‘collective memory, tradition’ and of ‘history-writing.’ Memory and time are important concepts in all three of the major historians whom we are treating, but perhaps most for Livy, whose history must have consumed all of his working life and, when intact, spanned the period from the sack of Troy through to the writer’s own day. He signals the importance of time from the start of his preface, which was published together with the first unit of his history: Facturusne operae pretium sim si a primordio urbis res populi Romani perscripserim nec satis scio nec, si sciam, dicere ausim . . . utcumque erit, iuuabit tamen rerum gestarum memoriae principis terrarum populi pro uirili parte et ipsum consuluisse (Praef. 1, 3, ‘Whether I will do something worthwhile if I write a detailed record of the deeds of the Roman people from the origin of the city I do not really know nor, if I knew, would I dare to say so . . . However that may be, it will nevertheless please me to have taken thought, to the best of my ability, for the history of the greatest nation in the world’). The tenses of the sentences quoted (facturus . . . sim, erit, iuuabit) put Livy’s own potential literary achievement and resulting profit firmly in the future: this preface looks ahead, towards the moment of publication and beyond, to the reaction readers will have to his book. Yet the force of the past is felt here, as well: it is memory (memoria rerum gestarum) with which Livy concerns himself, and that concern is imagined as having already happened (the perfect infinitive consuluisse): the preface is written as if from the simultaneous vantage points of one looking ahead and of one looking back on a task already completed.