He captured it in 1215, but it was not till 1284 that it was adopted as the imperial residence in lieu of Karakorum in the Mongol steppes by his grandson Kublai.
The Arka-tagh 1 is the true backbone of the Kuen-lun system, and in Central Asia is exceeded in elevation only by the Tang-la, a long way farther south, this last being probably an eastern wing of the Karakorum Mountains of the Pamirs region.
On arrival at the supreme Mongol court - either that on the Imyl river (near Lake Ala-kul and the present Russo-Chinese frontier in the Altai), or more probably at or near Karakorum itself, south-west of Lake Baikal - Andrew found Kuyuk Khan dead, poisoned, as the envoy supposed, by Batu's agents.
At nearly the same time Hayton, king of Armenia, made a journey to Karakorum in 1254, by a route far to the north of that followed by Carpini and Rubruquis.
The latter range is separated from the Karakorum Mountains by the deeply trenched gorge of the Raskem or Yarkand-darya, while the deep glen of the Kara-kash or Khotan-darya intervenes between the upper (Sughet Mountains) and the lower (Kilian Mountains) border-ranges.