A broad territorial base and security of possession are the guarantees of national survival. The geographic conditions which favor one often operate against the other. Peripheral location means a narrow base but a protected frontier along the sea; central location means opportunity for widening the territory, but it also means danger. A state embedded in the heart of a continent has, if strong, every prospect of radial expansion and the exercise of widespread influence; but if weak, its very existence is imperilled, because it is exposed to encroachments on every side. A central location minus the bulwark of natural boundaries enabled the kingdom of Poland to be devoured piecemeal by its voracious neighbors. The kingdom of Burgundy, always a state of fluctuating boundaries and shifting allegiances, fell at last a victim to its central location, and saw its name obliterated from the map. Hungary, which, in the year 1000, occupied a restricted inland location on the middle Danube, by the 14th century broke through the barriers of its close-hugging neighbors, and stretched its boundaries from the Adriatic to the Euxine; two hundred years later its territory contracted to a fragment before the encroachments of the Turks, but afterwards recovered in part its old dimensions. Germany has, in common with the little Sudanese state of Wadai, an influential and dangerous position. A central location in the Sudan has made Wadai accessible to the rich caravan trade from Tripoli and Barca on the north, from the great market town of Kano in Sokoto on the west, and from the Nile Valley and Red Sea on the east. But the little state has had to fight for its life against the aggressions of its western rival Bornu and its eastern neighbor Darfur. And now more formidable enemies menace it in the French, who have occupied the territory between it and Bornu, and the English, who have already caught Darfur in the dragnet of the Egyptian Sudan.[248] [Sidenote: Danger of central location.]