“It is a noble exercise to recount accurately the deeds of princes. To do so is to consider generously all that is subject to time, to celebrate the dead, to entertain the living, and to set out a past life as a model for later generations. It is to bring back what has happened in the past. When it displays victories, it confers them on the victorious. It eliminates sloth, conveys honesty, presents virtues and draws a crowd. We should, therefore, press forward with the greatest effort to read what has been written and to write down what ought to be read. Thus, in reading old things and writing new things, antiquity may be able to satisfy our needs and we may be able to nourish to the fullest the requirements of our posterity.”
--Ralph of Caen. Gesta Tancredi, Preface. Translated by Bernard S. Bachrach and David S. Bachrach (Burlington, VT: Ashgate, 2005), p. 19. [Emphasis added]
Here is some background from Matthew Phillips at Historia et Memoria
Ralph of Caen wrote one of the chronicles of the First Crusade in the
second decade of the twelfth century. Here he captures the essence of
the classical and Christian understanding of the purpose of history.
The writers of history should seek to bring back past events to recount
great deeds and give examples of virtuous behavior.