Even before the Christian era there had been a distinct differentiation between the ships of the Mediterranean and those of the Atlantic seaboard. The latter, as shown by Nicolas’ quotation from Cæsar, were more strongly built than the Roman galleys, with flatter bottoms, to “adapt them to the shallows and to sustain without danger the ebbing of the tide,” and with prows and sterns “very high and erect, to bear the hugeness of the waves”: properties which, even before the advent of fire artillery, conferred on them important advantages.[1] Nevertheless, complete differentiation did not obtain until after the discovery of gunpowder and the mariner’s needle. Before that time the vessels used by the Northern nations in war were of the galley type, built by themselves or, after the Crusades had revealed the superiority of the Mediterranean powers in warship design, hired not infrequently from Venetians or from Genoese. The Genoese were the chief naval mercenaries of Europe at this age: “Genoese were vice-admirals to the English king, and Genoese galleys fought for the French at Sluys.” The new type evolved in the Mediterranean was the _galleasse_. For centuries, as we have seen, large sailing ships had been used for commerce, both in the Atlantic and in the Mediterranean. With the inevitable increase in size brought about by the adoption of cannon, and by the desire for greater sea-keeping qualities, resort was now had by the Genoese and Venetians to sails in war vessels as a means of propulsion of equal importance with oars. Thus an uncomfortable compromise was effected between oars and sails; both were provided. The galleasse was originally a large decked galley, with three pole masts for its lateen sails, and with cannon spaced at intervals along its sides above the rowers. In form it differed little from the galley, but in the disposition of its armament it was entirely different; it represented the first stage in the evolution of the broadside fighting ship.