Complex sentence: However, there is a theory that Kumayl was imprisoned by Governor Ubayd Allah ibn Ziyad (no blood relation of Kumayl), because there are historical records of a person named Kumayl al-Hamadan'i, who was imprisoned by Ubayd Allah ibn Ziyad.
Split into simpler sentences: However, there is a theory that Kumayl was imprisoned by the governor Ubayd Allah ibn Ziyad (no blood relationship to Kumayl). Because there are historical record of a person named Kumayl al-Hamadan'i, who was imprisoned by Ubayd Allah ibn Ziyad.