Selected as a "Northern Capital" to contrast with Nanjing, for 10 points, name this city that contains the Forbidden Palace and is the current capital of China.
The Muslim architect Yeheidie'erding improved an urban planning design that had a drum tower mark the middle of this city, which was organized around six seas.  This city was the capital of the state of Yan before the Qin took over. Despite being undefended, this city was not captured by the leader of the Oirat Mongols during the Tumu Crisis, but it was occupied without much trouble by Li Zicheng. Following the enactment of three unequal treaties in this city, it added a Legation Quarter that was the target of a siege broken by the Eight Nation Army. Matteo Ricci was the first Westerner allowed to visit a particular location in this city. Selected as a "Northern Capital" to contrast with Nanjing, for 10 points, name this city that contains the Forbidden Palace and is the current capital of China.
The Muslim architect Yeheidie'erding improved an urban planning design that had a drum tower mark the middle of this city, which was organized around six seas.  
Beijing [or Ji; or Dadu; or Khanbaliq; or Peking; or Beiping] 