Intermission - The Historian as Man
Kipling on a particular failure of the Roman conquest
... And peace was imposed all over Southern Britain; and the legions came to be stationed only on the frontier, and hardly ever moved. No doubt at first these legions were recruited from all the regions over which Rome ruled, and she ruled from Euphrates to Tyne, from Rhine to Africa. Soon, however, they must have been recruited in Britain itself and from Britons. Celtic mothers bore British sons to Roman fathers, and crooned Celtic songs over the cradles of babies who would one day carry the Roman flag. The beautiful Latin tongue, which the Romans had brought with them, was enriched with many Celtic words.
It was, however, a misfortune for Britain that Rome never conquered the whole island. The great warrior Agricola did, between A.D. 79 and 85, penetrate far into Scotland; but he could leave no traces of civilization behind him, and Ireland he never touched at all. So Ireland never went to school, and has been a spoilt child ever since ...
Rudyard Kipling, Kipling's Pocket History of England