Roman Lincolnshire has no written history. There is not a line in any extant ancient writer describing the progress of a Roman army within its limits. Yet that wonderful people have left indelible marks of their presence in the county, not merely, as elsewhere, in a few fortifications connected by military roads, but in the systematic reclamation of a whole district. The details remaining to us of their conquest of the island apply principally to the south-east, the north, and the north-west. And yet the marshy plain of the Lincolnshire coast must have been then, as it proved in later times, an ideal refuge for native tribes at last driven to bay. Bounded on the east by the sea and on the south by impassable fens—subject in parts to submersion by the sea—the county was only accessible to a southern invader on its south-west side, through the forest which then covered Kesteven. But the Roman conqueror was seldom daunted by natural obstacles; and some further explanation is needed of the fact that, in the earlier stages of the conquest, his efforts seem constantly deflected to the west. Some have fancied that the Romans recognised their most implacable enemies in the Druids, and that these priestly fanatics retreated westward before them until they were finally exterminated by Paulinus in their stronghold of Mona (Anglesey). A simpler hypothesis is that, like the Regni in Sussex and the Brigantes in Yorkshire, the inhabitants of our county at first propitiated the enemy by alliance and by giving hostages for good conduct. The tribe which, according to Ptolemy (about A.D. 120), then occupied the counties of Lincoln, Leicester, and Nottingham, was the Coritani. If, as some have supposed, this tribe was a branch of the Eceni, it would almost certainly have been involved in the rebellion of Boudicca (A.D. 61). Yet for at least ten years we hear of no further expedition undertaken in this direction. If, on the other hand, the tribe was subject to or allied with its powerful northern neighbour, the Brigantes, it may possibly have been included in the compact which, before the year A.D. 50, was made by that tribe with the invader. Professor Rhys conjectures, rather hesitatingly,[11] that the Coritani may have been a remnant of the pre-Celtic population, and that their submission may have synchronised with the conquest of the warlike tribes of the southern midlands, to whom they had been subject.