The Christian stranglehold on the waters of the trunk routes in the eastern Mediterranean was ended in the thirteenth century when the Seljuq sultan Kai-Khusrau I broke out of the confines of the Anatolian plateau through to the Bay of Attalya during the chaos which engulfed the Byzantine empire after the Fourth Crusade. He captured Attalya in 1207 and, following this Seljuq seizure of a Mediterranean coastline, the Turks quickly took to the sea. Indeed it is quite remarkable just how soon after their acquisition of a coastline the sources record Turkish ships and seamen. These Muslims were certainly not restrained by their non-maritime cultural heritage from appreciating the sea. Letters exchanged between Hugh I of Cyprus and Kai-Kā'ūs I in 1214-16 refer to Turkish merchants and ships in the Mediterranean and to ships of the sultan. Clearly, Seljuq merchants and their ships began to ply the waters south to Cyprus, and perhaps to Egypt, in this period. Whether Turkish corsairs also began to operate in Levantine waters at the same time is not clear. Kai-Qubādh I pushed east along the coast to Alanya between 1220 and 1227, and the superb naval arsenal which he built at Alanya was almost certainly intended for the maintenance of corsair flotillas or coastguard patrols.