It is thought that Beijing roast duck, like the tradition of roast turkey in America and the UK, owes its origin to the roast goose that is still popular in Europe on festive occasions. Westerners like Marco Polo brought certain European customs to China and may have introduced the concept of roasting poultry to their Chinese hosts during the Yuan Dynasty (1271 - 1368).
Ducks had long been domesticated in China and the plump ducks proved to be an excellent substitute for goose.
However, there is another school of thought based upon certain records that show roast duck has a much longer history dating back as far as the Northern and Southern Dynasties (420 - 589).
Up until the Southern Song Dynasty (1127 - 1279), ducks were roasted in the area around Jinling, today's Nanjing. However, the later Yuan Dynasty rulers moved their capital city to Beijing from Jinling and took with them their cuisine thus making roast duck popular in the city that was eventually to make it its very own specialty.