The rule of Ban Culin is justly regarded as the brightest period in the annals of Christian Bosnia. His first care on his accession was to surround himself with trustworthy Župans and Voivodes, and during the thirty-six years of his reign Bosnia enjoyed a profound peace. Under his auspices and protection the merchants of Ragusa began to plant their factories in Bosnia, and open out anew the rich mines which had been left unworked since the days of the Romans. The very year after Culin’s accession, two Ragusan brothers built a factory and opened mines on the site of what has since become the capital of Bosnia.[12] Other mines were shortly opened in the neighbourhood, and a fortress, called after the Sclavonic name of their mother city, Dubrovnik, was built by the same enterprising merchants to protect their industries. The same wise policy encouraged another immigration, this time, of Saxon miners, who, like the Ragusans, did much to lay bare the great mineral wealth of this and the other Serbian lands, and who have left their traces in several old German mining expressions still current among the miners and mountaineers of Bosnia. These Saxons, or _Sasi_, settled chiefly in the towns, where their influence was valuable in instilling something of the civic unity of the free Teutonic burghs into the loosely compacted aggregation of hovels that clustered round the fortified ‘grad’ of the Bosnian lord.[13] Culin is said to have been the first Bosnian prince who struck coins, and the general prosperity was such that to this day ‘the times of good Ban Culin’ are invoked by the Bosniac when he wishes to express the golden age. But the patronage which Culin afforded to a religious sect that now becomes prominent in Bosnia makes his rule of still greater importance, and leads us to the consideration of a subject which has its bearings even on English history. The doctrine of the Two Principles of Good and Evil, which had its origin perhaps in the sublime mythology of Persia and the eternal conflict of Light and Darkness, held its own amongst the various Gnostic sects of Christianity, scattered throughout the Eastern world, while the West was content to slumber in comparative orthodoxy. In Armenia, where these doctrines had certain affinities with the earlier religion, they seem to have taken especially firm root; and here, as in the other border states of the Byzantine Empire, heterodoxy went hand in hand with patriotism. Considering the hostile relations in which both nations stood to Byzantium, it is not at all surprising that friendly communications should have subsisted between the Armenians and the Bulgarian Sclaves whose country lay to the east of the Serbians. Further, it was extremely natural that Armenians, for national as well as sectarian reasons, should view with jealousy the progress of orthodox missionaries among the Bulgarians, and should attempt to counteract it by organising a propaganda of their own Manichæism.