Uthman ibn Affan
When Umar was assassinated in 644, Uthman ibn Affan second cousin and twice son-in-law of Muhammad became the next caliph. As the Arabic language is written without vowels, speakers of different Arabic dialects and other languages recited the Quran with phonetic variations that could alter the meaning of the text. When Uthman ibn Affan became aware of this, he ordered a standard copy of the Quran to be prepared. Begun during his reign, the compilation of the Quran was finished some time between 650 and 656, and copies were sent out to the different centers of the expanding Islamic empire.