Answer: polo

AnswerCrossword Clue
POLOTraveler Marco
POLOSport not seen in the Olympics since 1936
POLOGame with four-player teams
POLOOlympic sport until 1936
POLOSport that originated in Persia
POLOHis travelogue never mentions the Great Wall of China, oddly
POLOExplorer who charmed Kublai Khan
POLOGame played on a 300-yard-long field
POLONoted traveler
POLOCompany whose logo includes a horse
POLOCompany with a horse in its logo
POLOSport with mallets
POLOGame with horses
POLOCasual shirt
POLOEquestrian sport
POLOGame on horseback
POLOPrince Charles's pastime
POLOSilk Road traveler
POLOTraveler of the 13th and 14th centuries
POLOCasual top
pologame played on horseback by two teams who drive a ball with long-handled mallets
POLOShirt with a collar that might be popped
POLOPrince Charles' sport
POLOTraveler to Cathay
POLOGame of chukkers
POLOGame played on horse-back
POLOWater sport
POLOGame with chukkers
POLOMarco ...
POLOLauren's brand
POLOGame similar to buzkashi, but played with a ball instead of a dead goat
POLOSport with mounts and mallets
POLOType of shirt that might have a popped collar
POLOSport of princes
POLOGame played in chukkers
POLOHorsemen's game
POLOGame marked by chukkers
POLOGame with mallets
POLOChukker game
POLOHorse play?