Complex sentence: At the time of conquest, polities in the northern Yucatán peninsula included Mani, Cehpech and Chakan; further east along the north coast were Ah Kin Chel, Cupul, and Chikinchel.
Split into simpler sentences: At the time of conquest, polities in the north included Mani, Cehpech and Chakan. Cehpech was a coastal province to its east; further east along the north coast were Ah Kin Chel, Cupul, and Chikinchel.