大公国出现于欧洲中世纪封建割据时期。

The Grand Duchy appeared in the feudal separation period during middle ages in Europe.

但蒙古贵族传统的分封制，导致了蒙古地区封建割据的形成和泛滥；

The tribute system of Mongolian aristocracy formed and increasing feudal separated jurisdiction in Mongol area.

大大地增加了他的财政收入，为他建立封建割据，掀起“七国之乱”提供了雄厚的物质基础。

Thus his revenue was greatly increased and it provided a strong material base for him to estadlish feabal seperationist rule and to surge "armed rebellion of seven countries".