Abrahah Al-Ashram was the governor of Yemen on the behalf of the king of Ethiopia. Abrahah thought to built a house of (like the Kabah) in Sana (the capital of Yemen) and call the Arabs to perform the pilgrimage here in Sana instead of Mecca, with intentions of diverting the trade and benefits from Mecca to Yemen. He presented the idea to the King of Ethiopia who agreed to it. So the so the house (church) was built and he named it Al-Qullais; at the time there was no church of its like.
Then a man from the tribe of Quraish came there and infuriated by it, so he revealed his nature (stool and urine) in it, soiled its walls and went away. When Abrahah saw that he could not control his anger and raised his army to invade Mecca and demolish the Kabah. He had in his army thirteen elephants and amongst them was an elephant called Mahmud which was the biggest of them. So that army proceeded and none amongst the Arab tribes was able to face them, because everyone who came to their way was slaughtered and destroyed, till in reached near Mecca. Then there took negotiations between Abrahah and Abdul Mutlib (grandfather of Prophet Muhammad PBUH), and it was concluded that Abrahah would restore the camels of Abdul Mutlib which he had taken away, and then Abraha would decide himself as regards the Kabah.
Abdul Mutlib ordered the men of Mecca to leave Mecca and go to the top of the mountains along with their wives and children. The army moved towards Mecca till they reached the valley of Muhassir, while they army was marching towards Mecca, in the middle of the valley, suddenly it was overtaken by flocks of birds, flocks after flocks, air-raiding that army with small stones. Every stone that fell on a solider dissolved his flesh and burst it into pieces. So they perished into total destruction.
Abraha fled away while his flesh was bursting into pieces and till he died on his way back to Yemen. Such was the victory bestowed by Allah, to the people of Mecca and such was the protection provided by him for his house.