The Kuren Dagh and Ala Dagh enclose the valley of the Atrek River, which flows west and southwest into the Caspian at Hassan Kuli Bay.
Nalzr Arsanas), rises south-west of Diadin, in the northern flank of the Ala Dagh (11,50o ft.), and flows west to the Alashgerd plain.
To N.E., has a length of about 290 m., and ends some distance beyond Bujnurd in northern Khorasan, where it joins the Ala Dagh range, which has a direction to the S.E., and, continuing with various appellations to northern Afghanistan, unites with the Paropamisus.
By the aid of these auxiliaries the fort of Ala Shehr was captured (1392), Manuel Palaeologus, son of the emperor, being allowed, in common with many other princes, the privilege of serving in the Turkish army, then the best organized and disciplined force extant.
The central range seems to be higher, culminating with the ShahJehan Kuh (1r,000) and the Ala Dagh (11,500).
The founder of the Mevlevi dancing dervishes, the poet Mahommed Jelal-ed-Din (Rumi), in 1307, though tempted to assume the inheritance along with the empire of the Seljuk sultan Ala ed-din Kaikobad III., who died without heirs, preferred to pass on the power to Osman, son of Ertogrul, and with his own hands invested Osman and girt him with the sword: this investiture was the legitimate beginning of the Osmanli authority.
Garcia was murdered by the sons of Count Vela of Ala va whom he had despoiled, and Sancho took possession of Castile, giving the government of it to his son Fernando, (Ferdinand I.), with the title of king, and taking the name of king of the Spains for himself.
He took Aidos, Nicomedia, Hereke, and, after a siege, Nicaea; Tarakli and Gemlik fell to his arms, and soon the whole of the shore of the Marmora up to Kartal was conquered, and the Byzantines retained on the continent of Asia Minor only Ala Shehr and Biga.
Zeno states that in the following year Ismail entered upon a new campaign in Kurdistan and Asia Minor, but that he returned to Tabriz without accomplishing his object, having been harassed by the tactics of Ala ud-Daula, a beylerbey, or governor in Armenia and parts of Syria.
The walls, largely the work of Ala ed-Din I., are preserved in great part and notable for the number of ancient inscriptions built into them.