Complex sentence: The situation was further confused by a second rebellion led by Govanni Asen Zaccaria, who claimed to be the'Prince of Achaia' representing the remains of the Latin element in the Morea, who was imprisoned by Thomas but managed to escape during the confusion.
Split into simpler sentences: The situation was further confused by a second rebellion led by Govanni Asen Zaccaria, who claimed to be the'Prince of Achaia' representing the remains of the Latin element in the Morea. Before the rebellion, Zaccaria was imprisoned by Thomas but managed to escape during the confusion.