it seemed advisable, with the view of preventing the appearance of the Germanic arms on the south of the Rhine, at least to show the Roman arms beyond it.  The protection which the fugitive Usipetes and Tencteri had found among the Sugambri afforded a suitable occasion.  In the region, apparently between Coblentz and Andernach, Caesar erected a bridge of piles over the Rhine and led his legions across from the Treverian to the Ubian territory.  Some smaller cantons gave in their submission; but the Sugambri, against whom the expedition was primarily directed, withdrew, on the approach of the Roman army, with those under their protection into the interior.  In like manner the powerful Suebian canton which oppressed the Ubii—­presumably the same which subsequently appears under the name of the Chatti—­caused the districts immediately adjoining the Ubian territory to be evacuated and the non-combatant portion of the people to be placed in safety, while all the men capable of arms were directed to assemble at the centre of the canton.  The Roman general had neither occasion nor desire to accept this challenge; his object—­partly to reconnoitre, partly to produce an impressive effect if possible upon the Germans, or at least on the Celts and his countrymen at home, by an expedition over the Rhine—­was substantially attained; after remaining eighteen days on the right bank of the Rhine he again arrived in Gaul and broke down the Rhine bridge behind him (699).

Expeditions to Britain

There remained the insular Celts.  From the close connection between them and the Celts of the continent, especially the maritime cantons, it may readily be conceived that they had at least sympathized with the national resistance, and that if they did not grant armed assistance to the patriots, they gave at any rate an honourable asylum in their sea-protected isle to every one who was no longer safe in his native land.  This certainly involved a danger, if not for the present, at any rate for the future; it seemed judicious—­if not to undertake the conquest of the island itself—­at any rate to conduct there also defensive operations by offensive means, and to show the islanders by a landing on the coast that the arm of the Romans reached even across the Channel.  The first Roman officer who entered Brittany, Publius Crassus had already (697) crossed thence to the “tin-islands” at the south-west point of England (Stilly islands); in the summer of 699 Caesar himself with only two legions crossed the Channel at its narrowest part.(42) He found the coast covered with masses of the enemy’s troops and sailed onward with his vessels; but the British war-chariots moved on quite as fast by land as the Roman galleys by sea, and it was only with the utmost difficulty that the Roman soldiers succeeded in gaining the shore in the face of the enemy, partly by wading, partly in boats, under the protection of the ships of war, which swept the beach with missiles thrown from machines