Gibbon's Italian journey of 1764 inaugurates the period which presents the greatest diffculties to his biographers. There are two sets of reasons for this. In the first place, the journal which he had begun to keep in camp with the militia breaks off at his arrival in Rome on 2 October 1764, and is never resumed, so that for the remainder of his life we are without this intermittent daily record of his studies and social activities, though not for some years without the manuscript essays on scholarly and historical subjects which he wrote in the course of the former. In the second place, his Memoirs, written many years later, make – and he persisted in making – important claims about his Roman experiences, in which he saw and obliges us to see the moment of conception of the Decline and Fall, but which in the absence of the journal are hard to document, validate or interpret. As a result, we face problems in tracing what the Decline and Fall began as being, what it became, and consequently what it was and is; and these problems extend beyond the sojourn at Rome, to the whole of the decade before Gibbon's first volume was published in 1776.