Martin Theodoor Houtsma, 1911 Encyclopædia Britannica (1911)
“ Masūd, the son of Izz ed-dīn, who on the death of his father had fled from the Crimea to the Mongol khān and had received from him the government of Sivās, Erzingān and Erzerūm during the lifetime of Kaikhosrau III., ascended the Seljūk throne on the death of Kaikhosrau. But his authority was scarcely respected in his own residence, for several Turkish amirs assumed independence and could only be subdued by Mongol aid, when they retired to the mountains, to reappear as soon as the Mongols were gone. ”
