Khanbaliq or Dadu was the winter capital of the Mongol-led Yuan dynasty in what is now Beijing, the capital of China today. It was located at the center of modern Beijing. The Secretariat directly administered the Central Region of the Yuan dynasty and dictated policies for the other provinces. As emperors of the Yuan dynasty, Kublai Khan and his successors also claimed supremacy over the entire Mongol Empire following the death of Möngke in 1259. Over time the unified empire gradually fragmented into a number of khanates.