For generation after generation, the Romans sent legion after legion of their soldiers into Britain. These legionaries were not all Italians. They were recruited from various parts of the Roman Empire. We know that one of the Roman emperors, holding command in Britain, took a woman of British birth to wife, and that Constantine the Great was their child. Are we asked to believe that the thousands upon thousands of Roman legionaries in Britain lived a life of celibacy, and left no descendants after them? The city of Lincoln was itself no mere military station but a Roman colony, Lindi Colonia, and the volume from which I quote shows that Lincolnshire has produced very extensive traces of its Roman occupation, civil as well as military. The county appears to have contained no fewer than six Roman military stations, and was traversed by four Roman roads. In the preceding lecture, I have alluded to that common illusion of popular history through which people are led to imagine that the migratory conquests of ancient times led to the extermination of the older inhabitants by the newcomers. On this same illusion, lodged in the mind of a man of scientific education, is based the notion that the Roman occupation left no mark, in the ethnographical sense, on the later population. We find the definite expression of this illusion in the words in which the writer professes to account for the total disappearance of the Celtic population of Lincolnshire, on whose people, he says, still speaking ethnographically, the Celts have probably left no impression. "The Brythons," he tells us, "fled before the Roman advance." Bear well in mind that we are now on the surer ground of history. The Roman conquest of Britain was completed by Agricola in the year 80 of the Christian era. We have the account of this conquest from a contemporary authority, Tacitus, who was son-in-law to the conqueror, Agricola. In a remarkable passage, Tacitus tells how the Britons behaved after Agricola had warred down their pride: