[Illustration: A PORTION OF THE ROCK MONASTERY, NOTTINGHAM PARK]. If I were to attempt to deal with castles and towns on rocky heights I would have to fill pages with descriptions of Capdenac, Najarc, Minerve, Les Baux, San Marino, San Leo, and many another, but inasmuch as they are _on_ rocks instead of being _in_ rocks, I must pass them over. A fourth class of cliff castle, neither the habitation of a _routier_ nor the residence of a feudal seigneur, is that which commands an important ford, or the road or waterway to a town, and which was, in point of fact, an outpost of the garrison. I can describe but a few. The Emperor Honorius had conceded to the Visigoths all that portion of Gaul that lay between the Loire and the Pyrenees. The Visigoths were Arians. Far from imitating the Romans, who respected the religion of the vanquished, and cared only that the peoples annexed to the Empire should submit to their administrative and military organisation, the Visigoths sought to impose Arianism on the nations over whom they exercised dominion. The bishops and priests protested energetically against this tyranny, and the Visigoths sought to break their resistance by persecution and exile, but gained nothing thereby save bitter hostility. In the year 511 an event took place that gave to the Aquitanians their religious liberty. The Franks were their deliverers. Clovis, who coveted the rich provinces of the South, profited by the religious antagonism existing between the Aquitanians and the Goths to gain the confidence of the bishops to whom he promised the destruction of Arian supremacy. And as he had obtained the strongest and most numerous adhesions in Poitou he resolved there to strike a decisive blow. He prepared his expedition with such secrecy and moved with such celerity that Alaric II., King of the Visigoths, did not become aware of his peril till the army of Clovis was on the confines of his realm. He threw himself into Poitiers, and assembled all the forces he was able to call together. Clovis crossed the Loire at Tours, and directed his march towards Poitiers; he passed over the Creusse at Port de Pilles, and reached the Vienne. The season was the end of September, and there had been so much and such continuous rain that the river was swollen, and he could not cross. Accordingly he and his army ascended it on the right bank seeking for a ford.