Two theories, both inherited from classical Greek and Roman scientific texts, underpinned the representation of the sea on medieval English maps. The first was that the known world, comprising Asia, Europe, and Africa, was surrounded by an encircling ocean, within which the islands of Britain and Ireland could be found. The second theory – distinct, but not necessarily incompatible with the first – was that the known world was just one of four land masses, which were divided by two oceans: an outer, encircling ocean ran from the north to the south pole, intersecting with another ocean that ran along the equator. Tides generated by the intersection of these two oceans were thought to flow from the centre of the earth to its northern and southern extremities. These theories found visual expression on the maps of the world (mappae mundi) produced in England and throughout much of continental Europe from at least 1000 to 1500, and in the zonal world map that typically illustrated copies of Macrobius’s widely disseminated commentary on Cicero’s Dream of Scipio. In the following pages, I will argue that both of these learned models contributed to the conceptualisation of the position of the British Isles in relation to the sea, and to other lands and peoples. However, I will also emphasise the importance of another genre of map for the question of the sea and English identity, one frequently marginalised in discussions of English cartography: the sea-chart. The kind of representation found on sea-charts, and in related genres, such as detailed written descriptions of coastlines, needs to be considered in relation to those of mappae mundi and Macrobian maps, not to perpetuate stale dichotomies between secular and religious world views, or between experience and theory, but so as to explore the diversity and richness of English geographical cultures from the twelfth to fifteenth centuries.

Ocean Flows

The ancient Greek notion of an encircling ocean was transmitted to Anglo-Saxon England through a fairly large number of classical and late antique texts. Bede, the Old English Orosius, and certain anonymous works all described an outer ocean, as well as interior seas.