Complex sentence: The Jizya used to be a tribute required of non-Muslim people under the protection of the Muslims which gave this lesser people group or society, unable to protect themselves from outside Muslim opposition, the option to submit to the Muslim people, and come under their protection.
Split into simpler sentences: The Jizya used to be a tribute required of non-Muslim people under the protection of the Muslims. A lesser people group or society, unable to protect themselves from outside Muslim opposition, are given the option to submit to the Muslim people, and come under their protection.