Complex sentence: Various versions are told about Nihavand and how the Muslims were being bested in the early stages of the battle but eventually managed to deceive the Persians through a ruse, that Caliph Omar had died.
Split into simpler sentences: Various versions are told about Nihavand and how the battle was ensued in the early stages. Some note that the Muslim Arabs managed to deceive the Persians through a ruse, that Caliph Omar had died.