What are the explanations for the success of the Arab Muslim armies?

Source 2
A painting

Source 3
A fragment

Source 4
A modern historian describes Arab tactics

Source 5
A catapult

Source 6
Hand grenades

Source 7
A ninth/third century Persian writer describes Arab tactics & methods

When the Arabs were divided they were no threat to anyone.
When they were united they became a major new power.

They believed that if they died fighting for Islam they would go straight to heaven

Many people whose countries had been taken by Byzantine and Persian Empires hated the rulers and welcomed the Muslim invaders as liberators.

Source 8
2 sayings of Muhammad*

Source 9
written by a modern historian

Source 10
An Arab general offers terms for surrender in the seventh/first century

Source 11
A modern Muslim writer describes the spread of Islam

Source 12
some rules of war laid down by Abu Bakr in the seventh/first century

Source 2
An Islamic city
Ankara in Turkey
about 1000 years after Muhammad*

What did the new capital look like?

Source 3
Reconstruction of the Round City at Baghdad

Baghdad grew very quickly.

Source 4
A map of Baghdad

What was life in Baghdad?

Source 5
2 eighth/second-century proverbs about buying a house in Baghdad

Source 6
from a description of ninth/third-century Baghdad

Source 7
a rich person's house

Source 8
a poor person's house