Classical References to the Geography of Roman Britain – Classical Geographia

This page contains some of the classical references to the geography of Britain:

  • Pliny’s Natural History
  • Cassius Dio’s History of Rome
  • Caesar’s Gallic Wars

Gaius Plinius Secundus’s Natural History

Pliny Naturalis Historia  book on the Geography of the Roman Empire was written during the late 70’s AD.

Liber IV XVI.102

“Opposite to this region [the Rhine delta] lies the island of Britannia, famous in the Greek records and in our own; it lies to the north-west, facing, across a wide channel, Germania, Gallia and Hispania, 1 countries which constitute by far the greater part of Europe. It was itself named Albion, while all the islands about which we shall soon briefly speak were called the Britanniae. Its distance from Gesoriacum on the coast of the Morini tribe by the shortest passage is 50 miles. 2 Its circumference is reported by Pytheas and Isidorus to measure 4,875 miles; 3 nearly thirty years ago, its exploration was carried by the armed forces of Rome to a point not beyond the neighbourhood of the Silvae Caledoniae. 4 Agrippa believes the length of the island to be 800 miles and its breadth 300, and the breadth of Hibernia the same but its length 200 miles less. 5

  1. Germany, France and Spain respectively.
  2. Gesoriacum of the Morini is now the busy French port of Boulogne; the distance reported is clearly exaggerated, showing that Pliny had no first-hand experience of the area and was using an older, inaccurate reference source.
  3. This is equivalent to 4,480 English miles or 7,215 kilometers. All distances are of course given in Roman miles, and can be converted into the modern English equivalent by multiplying by 0.919. To convert into kilometers multiply by 1.48.
  4. The ‘Forest of Caledonia’ here mentioned, probably means the Grampian Foothills in the Central region of Scotland.
  5. Hibernia or Ireland, therefore, was thought to measure 276 by 184 English miles (444 by 296 kilometres).


“Hibernia lies beyond Britannia, the shortest crossing being from the lands of the Silures, a distance of 30 miles. 1 Of those remaining (islands) none has a circumference exceeding 125 miles, so it has been said. Indeed, there are 40 Orcades [Orkneys] separated narrowly from one another, 7 Acmodae [Shetlands], 30 Hebudes [Hebrides], and between Hibernia and Britannia (the islands of) Mona [Anglesey], Monapia [Man], Riginia [Racklin], Vectis [White-horn], Silumnus [Dalkey] and Andros [Bardsey]; beneath (Britain) are Sambis [Sian] and Axanthos [Ushant], and in the oppposite direction, sprinkled in the Mare Germanicum [North Sea], are the Glaesariae [Glass Islands], called by the Greeks in recent times the Electrides, from the amber 2 which is produced there.”

  1. The crossing to Ireland was actually made from the lands of the Demetae who inhabited Dyfed in south-west Wales, whereas the Silures tribe lived in the mountains of Glamorgan and Gwent in south-east Wales.
  2. The greek word for amber is electrum.


“The most remote of all those recorded is Thule, 1 in which as we have pointed out there are no nights at midsummer when the sun is passing through the sign of the Crab, and on the other hand no days at midwinter; indeed some writers think this is the case for periods of six months at a time without a break. The historian Timaeus says there is an island named Mictis 2 lying inward six days’ sail from Britain where tin is found, and to which the Britons cross in boats of osier covered with stitched hides. Some writers speak of other islands as well, the Scandiae, Dumna, Bergos, 3 and Berrice, 4 the largest of them all, from which the crossing to Thule starts. One day’s sail from Thule is the frozen ocean, called by some the Mare Cronium [Chronian Sea].”

  1. Probably Iceland, judging from the following description.
  2. Very likely St. Michael’s Mount, a small island off Marazion in Cornwall.
  3. Possibly Barra.
  4. Possibly the Isle of Lewis in the Outer Hebrides.

Cassius Dio’s History of Rome

The Location of Britannia

“This country is 450 stades [60 miles] distant, by the shortest way, from the Belgic mainland, where the Morini dwell, and extends alongside the rest of Gaul and nearly all of Spain, reaching out into the sea.” (Dio Ιστορια  XXXIX.l.2)

Proven to be an Island

“Meanwhile war had again broken out in Britain, and Gnaeus Julius Agricola overran the whole of the enemy’s territory there. He was the first of the Romans whom we know to discover the fact that Britain is surrounded by water. It seems that some soldiers rebelled, and after slaying the centurions and a military tribune took refuge in boats, in which they put out to sea and sailed round the western portion of the country just as the wind and the waves chanced to carry them: and without realizing it, since they approached from the opposite direction, they put in at the camps on the first side again. Thereupon Agricola sent others to attempt the voyage around Britain, and learned from them, too, that it was an island.” (Dio Ιστορια  LXVI.xx.1-2)

The Size of Britain

“… Its length is 7,132 stades, its greatest breadth 2,310, and its least 300¹. Of all this territory we hold a little less than one half.” (Dio Ιστορια  LXXVII.xii.5)

  1. These distances are 951, 308 and 40 miles respectively; calculated at 7½ stades to the mile.

Caesar’s Gallic Wars

Description of Britain, its inhabitants, their customs and tribal institutions, also the geography of the island:

[5.12] The interior portion of Britain is inhabited by those of whom they say that it is handed down by tradition that they were born in the island itself: the maritime portion by those who had passed over from the country of the Belgae for the purpose of plunder and making war; almost all of whom are called by the names of those states from which being sprung they went thither, and having waged war, continued there and began to cultivate the lands. The number of the people is countless, and their buildings exceedingly numerous, for the most part very like those of the Gauls: the number of cattle is great. They use either brass or iron rings, determined at a certain weight, as their money. Tin is produced in the midland regions; in the maritime, iron; but the quantity of it is small: they employ brass, which is imported. There, as in Gaul, is timber of every description, except beech and fir. They do not regard it lawful to eat the hare, and the cock, and the goose; they, however, breed them for amusement and pleasure. The climate is more temperate than in Gaul, the colds being less severe. [5.13] “The island is triangular in its form, and one of its sides is opposite to Gaul. One angle of this side, which is in Kent, whither almost all ships from Gaul are directed, [looks] to the east; the lower looks to the south. This side extends about 500 miles. Another side lies toward Spain and the west, on which part is Ireland, less, as is reckoned, than Britain, by one half: but the passage [from it] into Britain is of equal distance with that from Gaul. In the middle of this voyage, is an island, which is called Mona: many smaller islands besides are supposed to lie [there], of which islands some have written that at the time of the winter solstice it is night there for thirty consecutive days. We, in our inquiries about that matter, ascertained nothing, except that, by accurate measurements with water, we perceived the nights to be shorter there than on the continent. The length of this side, as their account states, is 700 miles. The third side is toward the north, to which portion of the island no land is opposite; but an angle of that side looks principally toward Germany. This side is considered to be 800 miles in length. Thus the whole island is [about] 2,000 miles in circumference. [5.14] “The most civilized of all these nations are they who inhabit Kent, which is entirely a maritime district, nor do they differ much from the Gallic customs. Most of the inland inhabitants do not sow corn, but live on milk and flesh, and are clad with skins. All the Britains, indeed, dye themselves with wood, which occasions a bluish color, and thereby have a more terrible appearance in fight. They wear their hair long, and have every part of their body shaved except their head and upper lip. Ten and even twelve have wives common to them, and particularly brothers among brothers, and parents among their children; but if there be any issue by these wives, they are reputed to be the children of those by whom respectively each was first espoused when a virgin.” (Caesar De Bello Gallico v.12-13)

  1. All British tribes apart from those living in Cantium (Kent).

Description of an Oppidum

“… Now the Britanni call it an Oppidum when they have fortified a thick set woodland with rampart and trench, and thither it is their custom to collect, in order to avoid a hostile inroad. …” (Caesar De Bello Gallico v.21)