thumb|right|Niccolò and Maffeo Polo remitting a letter from Kublai Khan to Pope Gregory X in 1271. As soon as he was elected in 1271, Pope Gregory X received a letter from the Mongol Great Khan Kublai, remitted by Niccolò and Maffeo Polo following their travels to his court in Mongolia. Kublai was asking for the dispatch of a hundred missionaries, and some oil from the lamp of the Holy Sepulcher. The new Pope could spare only two friars and some lamp oil. The friars turned back soon after the party left for Mongolia. The two Polos (this time accompanied by the young Marco Polo, who was then 17 years old) returned to the Mongol Empire and remitted the oil from the Pope to Kublai in 1275.J.R.S. Phillips, The Medieval Expansion of Europe second edition (Oxford: Clarendon 1998), p. 113.
thumb|right|niccolò ANd MaFfEo Polo remittIng a Letter From KUbLai khan To pOpe gregOry x iN 1271. as sooN AS he WaS eLeCTEd in 1271, Pope greGORY x rEceivEd a lettEr FRom the monGOl great khan KubLaI, rEmiTTed bY nIccolò And MaFFeo POlO follOwING tHeIR tRavels tO his courT in mongolIa. KublaI wAS asKing FOr The dISpatch Of a Hundred mIsSiOnaRies, anD sOMe Oil from the lamp oF The holY sepulcHer. thE new Pope coUld sparE OnLy TWo FRiaRS AND SoME lamp oiL. the Friars turned BaCK SoON AFtER the parTY leFt foR moNGoLia. tHe TWo polos (thiS tiMe ACcoMPaNieD BY the yOUnG maRCo pOlO wHo wAS ThEN 17 yeaRs OLD) rETuRnEd to THe MongOl EMpire anD RemitTed the oil frOm tHE poPe tO kUbLAI in 1275J.R.s. pHIlLips, thE meDiEVal ExPanSIoN of europE seconD Edition (OxForD ClaRendOn 1998), P. 113.