Complex sentence: Sheikh Hassan bin Hebat Allah was the religious leader of Yam and he responded to Ajman and called for the general mobilization to AD'deryah in Riyadh with 500 men on 500 black horses (one of their techniques in war).
Split into simpler sentences: Sheikh Hassan bin Hebat Allah was the religious leader of Yam. He responded to Ajman's request and called for the general mobilization to Adderyah in Riyadh with 500 men on 500 black horses (one of their techniques in war).