Complex sentence: At that time Abraha, the Christian ruler of Yemen marched upon the Kaaba, intending to demolish it, with a large army, which included one or more elephants, (as many as eight, in some accounts).
Split into simpler sentences: At that time Abraha, the Christian ruler of Yemen marched upon the Kaaba, intending to demolish it. He had a large army, which included one or more elephants, (as many as eight, in some accounts).