Complex sentence: Kublai moved his headquarters to Dadu, the genesis for what later became the modern city of Beijing, although his establishment of a capital there was a controversial move to many Mongols who accused him of being too closely tied to Chinese culture.
Split into simpler sentences: Kublai moved his headquarters to Dadu, the genesis for what later became the modern city of Beijing. His establishment of a capital there was a controversial move to many Mongols who accused him of being too closely tied to Chinese culture.