A gigantic army landed near the spot where Cæsar had landed just a hundred years before. The discovery and conquest of Britain now began in real earnest. The Isle of Wight was overrun by Romans; the south coast was explored. Roman soldiers lost their lives in the bogs and swamps of Gloucestershire. The eastern counties, after fierce opposition, submitted at the last. The spirit of Caractacus and Boadicea spread from tribe to tribe and the Romans were constantly assailed. But gradually they swept the island. They reached the banks of the river Tyne; they crossed the Tweed and explored as far as the Firths of Clyde and Forth. From the coast of Galloway the Romans beheld for the first time the dim outline of the Irish coast. In the year 88 Agricola, a new Roman commander, made his way beyond the Firth of Forth.

"Now is the time to penetrate into the heart of Caledonia and to discover the utmost limits of Britain," cried the Romans, as they began their advance to the Highlands of Scotland. While a Roman fleet surveyed the coasts and harbours, Agricola led his men up the valley of the Tay to the edge of the Highlands, but he could not follow the savage Caledonians into their rugged and inaccessible mountains. To the north of Scotland they never penetrated, and no part of Ireland ever came under Roman sway, in that air "the Roman eagle never fluttered." The Roman account of Britain at this time is interesting. "Britain," says Tacitus, "the largest of all the islands which have come within the knowledge of the Romans, stretches on the east towards Germany, on the west towards Spain, and on the south it is even within sight of France. . . . The Roman fleet, at this period first sailing round this remotest coast, gave certain proof that Britain was an island, and at the same time discovered and subdued the Orkney Islands, till then unknown. Thule was also distinctly seen, which winter and eternal snow had hitherto concealed. . . . The sky in this country is deformed by clouds and frequent rains; but the cold is never extremely rigorous. The earth yields gold and silver and other metals—the ocean produces pearls."

The account of Ireland is only from hearsay. "This island," continues Tacitus, "is less than Britain, but larger than those of Our Sea. Situated between Britain and Spain and lying commodiously to the Bay of Biscay, it would have formed a very beneficial connection between the most powerful parts of the Empire. Its soil, climate, and the manners and dispositions of its inhabitants are little different from those of Britain. Its ports and harbors are better known from the concourse of merchants for purposes of commerce."

Not only the British Isles, but a good deal of the wild North Sea and the low-lying coast on the opposite side were explored by Roman ships and Roman soldiers. Cæsar had crossed the Rhine; he had heard of a great forest which took a man four months to cross, and in 16 a Roman general, Drusus, penetrated into the interior of Germany. Drusus crossed the Rhine near the coast, made his way across the river Weser, and reached the banks of the Elbe. But the fame of Drusus rests mainly on his navigation of the German Ocean or North Sea in a Roman fleet. Near the mouth of the Rhine a thousand ships were quickly built by expert Romans. Some were short, with narrow stern and prow and broad in the middle, the easier to endure the shock of the waves; some had flat bottoms that without damage they might run aground; many were fitted for carrying horses and provisions, convenient for sails and swift with oars."

The Roman troops were in high spirits as they launched their splendid fleet on the Northern Ocean and sailed prosperously to the mouth of the Elbe, startling the Frisians into submission. But no friendliness greeted them on the farther side of the river. The Germans were ready to defend their land, and further advance was impossible. Returning along the northern coast, the Romans got a taste of the storms of this northern ocean, of which they were in such complete ignorance.

"The sea, at first calm," says Tacitus, "resounded with the oars of a thousand ships; but presently a shower of hail poured down from a black mass of clouds, at the same time storms raging on all sides in every variety, the billows rolling now here, now there, obstructed the view and made it impossible to manage the ships. The whole expanse of air and sea was swept by a south-west wind, which, deriving strength from the mountainous regions of Germany, its deep rivers and boundless tract of clouded atmosphere, and rendered still harsher by the rigour of the neighbouring north, tore away the ships, scattered and drove them into the open ocean or upon islands dangerous from precipitous rocks or hidden sandbanks. Having got a little clear of these, but with great difficulty, the tide turning and flowing in the same direction as that in which the wind blew, they were unable to ride at anchor or bale out the water that broke in upon them; horses, beasts of burthen, baggage, even arms were thrown overboard to lighten the holds of the ships, which took in water at their sides, and from the waves, too, running over them. Around were either shores inhabited by enemies, or a sea so vast and unfathomable as to be supposed the limit of the world and unbounded by lands. Part of the fleet was swallowed up; many were driven upon remote islands, where the men perished through famine. The galley of Drusus or, as he was hereafter called, Germanicus, alone reached the mouth of the Weser. Both day and night, amid the rocks and prominences of the shore, he reproached himself as the author of such overwhelming destruction, and was hardly restrained by his friends from destroying himself in the same sea. At last, with the returning tide and a favouring gale, the shattered ships returned, almost all destitute or with garments spread for sails."

The wreck of the Roman fleet in the North Sea made a deep impression on the Roman capital, and many a garbled story of the "extreme parts of the world" was circulated throughout the Empire.

Here was new land outside the boundaries of the Empire—country great with possibilities. Pliny, writer of the Natural History, now arises and endeavours to clear the minds of his countrymen by some account of these northern regions. Strabo had been dead some fifty years, and the Empire had grown since his days. But Pliny has news of land beyond the Elbe. He can tell us of Scandinavia, "an island of unknown extent," of Norway, another island, "the inhabitants of which sailed as far as Thule," of the Seamen or Swedes who lived in the "northern half of the world."

"It is madness to harass the mind with attempts to measure the world," he asserts, but he proceeds to tell us the size of the world as accepted by him. "Our part of the earth, floating as it were in the ocean, which surrounds it, stretching out to the greatest extent from India to the Pillars at Cadiz, is eight thousand five hundred and sixty-eight miles . . . the breadth from south to north is commonly supposed to be half its length."

But how little was known of the north of Europe at this time is shown by a startling statement that "certain Indians sailing from India for the purposes of commerce had been driven by tempests into Germany."

"Thus it appears," concludes Pliny, "that the seas flow completely round the globe and divide it into two parts."

How Balbus discovered and claimed for the Empire some of the African desert is related by Pliny. He tells us, too, how another Roman general left the west coast of Africa, marched for ten days, reached Mt. Atlas, and "in a desert of dark-coloured sand met a river which he supposed to be the Niger."

The home of the Ethiopians in Africa likewise interested Pliny.

"There can be no doubt that the Ethiopians are scorched by their vicinity to the sun's heat, and that they are born like persons who have been burned, with beard and hair frizzled, while in the opposite and frozen parts of the earth there are nations with white skins and long light hair."

Pliny's geography was the basis of much mediæval writing, and his knowledge of the course of the Niger remained unchallenged, till Mungo Park rediscovered it many centuries after.