That this was the case in the northern region is proved by the long survival of the name Chaldia (= Khaldia) among those inhospitable heights. Professor Lehmann has collected with a thoroughness of which his countrymen alone seem capable, a catalogue of passages in Greek and Byzantine writers making mention either of the Chaldian people or of the province to which they gave their name. [78] That people are sometimes called Chaldæans in classical authors. But that this was an error seems sufficiently proved by the name of the province--Chaldia; by the survival side by side of the variant form--Chaldians, and by the practice of Armenian writers to distinguish between the name of the tribe on their northern frontiers and that of the Chaldæans. Chaldia with the capital Trebizond formed one of the military themes of the Byzantine empire; and I should like to add yet another reference to the lists of Professor Lehmann, this one taken from the travels of the Castilian ambassador, Don Ruy Gonzalez Clavigo, in the year 1404. Setting out from Trebizond on his way to Erzinjan, we find him travelling on the third day out through the snowy mountains of the province of Chaldia to the castle of Tzanich which stood on a crag; and on the morrow, in the evening, he arrives at the castle of the duke of Chaldia, where all caravans pay toll. The territory formed a part of the empire of the Grand Comneni; and the name has survived to the present day as that of a diocese of the Greek Church with the capital Gümüshkhaneh on the road from Trebizond to Baiburt. [79]