Political-Economic Relation p.50

In the course of this single expedition all the modes of exchange are clearly evident: the formal presentation of tribute and exotica; government trade capitalized by the royal treasury; "private” commerce, involving semi-official merchant capitalists like Jamāl al-Dīn, whose transportation costs were underwritten by the imperial court; and, finally, the transfer of proceeds from long-established allotted territories, those princely shares in the profits of empire. While exact numbers are lacking, the account of this embassy provides arresting anecdotal evidence that the volume of exchange between the two courts could reach impressive levels, thus providing yet another reason for these two Chinggisid lines to remain in contact and maintain their partnershipand alliance.