Was Islam a peaceful religion in the beginning?
The Rashidun Empire reached its greatest extent under Caliph Uthman, in 654 (from here).
Early Muslim conquests
Rashidun Caliphate - Military expansion
Conquest of the Persian empire
Wars against the Byzantine empire
Conquest of Byzantine Syria
Occupation of Anatolia
Conquest of Egypt
Conquest of North Africa
Campaign against Nubia (Sudan)
Conquest of the islands of the Mediterranean Sea
First Muslim invasion of the Iberian peninsula
Treatment of conquered peoples
Paul, the Christian equivalent to Mohammed
The Penalties for Apostasy in Islam