That narrow strip of herbage strown, between the desert and the sown, are the sand-dunes, _shats_, and oases of the Tunisian Sahara. Of these five districts, the most important from an agricultural point of view is the Sahel. This narrow coastal plain, whose _chef-lieu_ is Sousse, is a region of almost inexhaustible productiveness, a fat land, a land of live stock, grain, fruit, and vine. For ages past the rich earth has been washed down from the hills to collect along the shore in deep layers of alluvial soil, which, scratched and watered, becomes a Garden of the Lord. That portion of the Sahel in the vicinity of Sousse is one vast forest of olive-trees. For miles we motored between the ordered gray-green rows, the trees so old, so bent, so gnarled, so twisted, that they might well have been planted by the Romans. Nor, indeed, is that at all improbable, for olive-trees frequently attain enormous age. In the Garden of Gethsemane, above Jerusalem, the monks reverently point out two venerable olive-trees beneath which, they assert, Christ was accustomed to converse with His disciples. Sousse, the second most important city of Tunisia, is a charming place. Its buildings, white as though cut from chalk, are set on the slopes of a natural amphitheater which rises quite sharply from the harbor, so that, seen from the sea, it bears a certain resemblance to Algiers. The Hadrumetum of the ancients, it was already old when Dido ruled at Carthage; it was hoary with antiquity when London was a cluster of wattle huts inhabited by painted savages, when Paris had yet to be founded amid the swamps beside the Seine. In the beginning a Phenician commercial outpost, established by merchants trading out of Tyre, it become a Roman colony under Trajan and so remained until the second century of the Empire, when the Vandals came. But the Vandals were driven out by Belisarius the Byzantine; and the Byzantines, in their turn, gave way before the fierce onslaught of the Arab hosts; whereupon the crescent replaced the cross, its churches were destroyed or converted into mosques, the Citadel was renamed the Kasbah, and Sousse became a corsair stronghold, one of its rulers being the terrible Dragut, the most feared sea-rover of his time.