What is "kokochin"

Kököchin, also Kökechin, Kokachin or Cocacin (Mn: Хөхөхчин, Ch: 阔阔真), was a 13th-century Mongol princess from the Yuan dynasty in China, belonging to the Mongol tribe of the Bayaut (Ch: 伯牙吾). In 1291, she was betrothed to the Ilkhanate khan Arghun by the Mongol Great Khan Kublai. This followed a request by Arghun to his grand-uncle Kublai, following the loss of his favourite wife Bolgana ("Zibeline"): Arghun asked Kublai Khan to send him a relative of his dead wife, and Kublai chose the 17-year-old Kökötchin ("Blue, or Celestial, Dame").

Kublai, from his capital of Khanbaliq (the Khan's city, modern day Beijing) entrusted Marco Polo with his last duty, to escort princess Kökechin to Arghun. The party travelled by sea, departing from the southern port city of Quanzhou in the spring of 1291. There were 14 big ships in all, and each had 4 masts and 12 sails. They set out from Quanzhou, sailing to Sumatra, and then to Persia, via Sri Lanka and India (where his visits included Mylapore, Madurai and Alleppey, which he nicknamed Venice of the East). They arrived around 1293.

Arghun had died in the meantime however, and Kököchin married Arghun's son Ghazan. She became his principal wife.