If we may implicitly trust the report of Caesar, a British city in his time differed widely from what we understand by that term. A spot difficult of access from the trees which filled it, surrounded with a rampart and a ditch, and which offered a refuge from the sudden incursions of an enemy, could be dignified by the name of an _oppidum_, and form the metropolis of Cassivelaunus[754]. Such also among the Slavonians were the _vici_, encircled by an _abbatis_ of timber, or at most a paling, proper to repel not only an unexpected attack, but even capable of resisting for a time the onset of practised forces: such in our own time have been found the stockades of the Burmese, and the Pah of the New Zealander: and if our skilful engineers have experienced no contemptible resistance, and the lives of many brave and disciplined men have been sacrificed in their reduction, we may admit that even the _oppida_ of Cassivelaunus, or Caratac or Galgacus, might, as fortresses, have serious claims to the attention of a Roman commander. But such an _oppidum_ is no town or city in the sense in which those words are contemplated throughout this chapter: by a town I certainly intend a place enclosed in some manner, and even fortified: but much more those who dwell together in such a place, and the means by which they either rule themselves, or are ruled. I mean a metaphysical as well as a physical unit,—not exclusively what was a collection of dwellings or a fortification, but a centre of trade and manufacture and civilization. ----- Footnote 754: Bell. Gall. v. 21. Caesar stormed it, and had therefore good means of knowing what it was. His further information was probably derived from his British ally Comius. Strabo gives a very similar account: πόλεις δ’ αὐτων εἰσιν οἱ δρυμοι’· περιφράξαντες γὰρ δένδρεσι καταβεβλημένοις εὐρυχωρῆ κύκλον καλυβοποιοῦνται, καὶ τὰ βοσκήματα κατκσταθμέυουσιν, οὐ πρὸς πολὺν χρόνον. lib. iv. ----- If the Romans found none such, at least they left them, in every part of Britain. The record of their gradual and successive advance shows that, partly with a politic view of securing their conquests, partly with the necessary aim of conciliating their soldiery, they did establish numerous _municipia_ and _coloniae_ here, as well as military stations which in time became the nuclei of towns.