Having first attempted to intimidate the Mantineans by ravaging their lands, Agesipolis commenced the work of blockade by digging a ditch around the town; half of his soldiers being kept on guard, while the rest worked with the spade. The ditch being completed, he prepared to erect a wall of circumvallation. But being apprised that the preceding harvest had been so good, as to leave a large stock of provision in the town, and to render the process of starving it out tedious both for Sparta and for her allies,—he tried a more rapid method of accomplishing his object. As the river Ophis, of considerable breadth for a Grecian stream, passed through the middle of the town, he dammed up its efflux on the lower side;[90] thus causing it to inundate the interior of the city and threaten the stability of the walls; which seem to have been of no great height, and built of sun-burnt bricks. Disappointed in their application to Athens for aid,[91] and unable to provide extraneous support for their tottering towers, the Mantineans were compelled to solicit a capitulation. But Agesipolis now refused to grant the request, except on condition that not only the fortifications of their city, but the city itself, should be in great part demolished; and that the inhabitants should be re-distributed into those five villages, which had been brought together, many years before, to form the aggregate city of Mantinea. To this also the Mantineans were obliged to submit, and the capitulation was ratified. [90] In 1627, during the Thirty years’ War, the German town of Wolfenbüttel was constrained to surrender in the same manner, by damming up the river Ocker which flowed through it; a contrivance of General Count Pappenheim, the Austrian besieging commander. See Colonel Mitchell’s Life of Wallenstein, p. 107.