In ancient Sumerian society, the social classes were organized into a strict hierarchy.
At that time, the social classes were divided into three groups called as estates. The first estate was of clergy, the second estate was of nobility and the third estate consisted of other classes ...
Columbus joins his brother in Lisbon, after his ship had sunk in the battle with pirates off Portugal, he had to swim ashore in order to survive.
I hope this helps.
The leaders who spread Islam after Muhammad's death were Abu Bakr, Umar, Uthman, and Ali. If you want the answer from a website, I suggest going here
--> http://peopleof.oureverydaylife.com/led-islamic-world-after-muhammad-died-7743.html <-- I hope this answer helps you.
