THE COAST BETWEEN CALAIS AND THE SOMME IN THE TIME OF CAESAR
The question of the period during which the gulf of St. Omer existed has given rise to much discussion. According to Reclus,[2448] Desjardins,[2449] and many other writers,[2450] even in the time of Caesar this so-called gulf, which was really a shallow salt-water ‘mere’, covered the lowlands north-east of the hills of Artois between Sangatte and Dunkirk, and extended inland to within a short distance of St. Omer. No evidence, however, has been adduced to show that it existed at that time;[2451] and it has been proved by M. J. Gosselet that it did not exist before the latter part of the third century of our era, for Gallo-Roman remains, including 2,354 coins, some of which belong to the time of Postumus, have been found in the area. As M. Gosselet says,[2452] the Sinus Itius is a mere invention of writers of the seventeenth century.
The ancient topography of Wissant, of the estuary of the Liane, and of the headlands of Blancnez, Grisnez, and Alprech, is discussed in the article on the Portus Itius.[2453]
The inland extension of the bay formed by the estuary of the Canche has steadily diminished since the time of Caesar; and whereas, during the last century at all events, the headland on its southern side has gained considerably on the sea, the ‘Pointe de Lornel’ on the north and the neighbouring sand-dunes have suffered continual erosion.[2454]
The country which lies between the hills of Artois and the sea, from the mouth of the Canche to the mouth of the Somme, is, as Reclus[2455] remarks, of recent formation; and, as late as the ninth century, the environs of the town of Rue, which is now about six miles from the sea, were covered by a vast shallow lake, 20,000 hectares, or about 78 square miles, in extent.