The Ragusans were essentially a commercial people, and trade, both inland and sea-borne, formed the chief source of their wealth. In the Byzantine period, however, we only find the germs of their future commercial development. We have already alluded to the part played by Ragusan shipping, first in the Greek expedition to Apulia in 848, and then at the battle of Durazzo. But the vessels were small, and the sea-borne trade of a very limited character. Navigation was of three kinds—coastwise traffic, navigation _intra Culfum_, and navigation _extra Culfum_.[91] Coastwise traffic was comprised between the peninsula of Molonta (a little to the north-west of the Bay of Cattaro) and the Canale di Stagno, a distance of about 70 kilometres in all, with ten harbours. Navigation _intra Culfum_, which extended from the Capo Cumano to Apulia and Durazzo, was of considerable importance even during the Byzantine epoch. Fine Milan cloths, skins, tan, and canvas for sails were brought on Ragusan ships from the ports of the Marche and Apulia, and forwarded to all parts of the Eastern Empire and the Slavonic lands. All trade to places situated beyond these limits came under the heading of navigation _extra Culfum_, but we shall defer a detailed account of its conditions to a later chapter, as it did not grow to important proportions until the thirteenth century. There was, however, apparently a Ragusan colony at Constantinople. [Illustration: THE QUAY AND HARBOUR GATE] The earliest recorded commercial treaty made by the Republic is the one of 1169 with Pisa. In 1168 the Republic of Pisa sent three envoys to Constantinople to settle a contention with Manuel Comnenus. On the way they stopped at Ragusa, and on May 13, 1169, signed a commercial treaty with the city, guaranteeing mutual immunities and other privileges. The Pisan envoys then proceeded on their journey, accompanied by the newly appointed chief of the Ragusan colony in the Imperial capital.[92] There were political as well as commercial reasons for this agreement, in the hostility of both Republics to Venetian supremacy in the Adriatic. About this time the Ragusans obtained the right of citizenship at Constantinople, granted to them by Manuel, and confirmed by his son, Alexius II. The original documents have not been preserved, but the privilege is frequently alluded to by later writers. Many treaties with the other towns of Dalmatia, Istria, and Italy are published in the _Monumenta spectantia Historiam Slavorum Meridionalium_. Thus in 1188 a perpetual peace was concluded with Rovigno;[93] in 1190 an agreement with the Cazichi or Narentans[94] (also called Dalmisiani, from the town of Almissa); in 1191 a treaty with Fano, and others to which we have already alluded. These agreements were all similar in character, and their object being to insure mutual and commercial privileges. Some contained special clauses exempting the citizens of the contracting cities from certain taxes and customs dues.