This contrasts with the Shi'a Muslim belief that Muhammad himself appointed his first successor to be Ali ibn Abi Talib as the first Caliph and the first Muslim imam (David Krusch). Abu Bakr survived for about two years. Then three more caliphs followed 'Umar, 'Uthman, and 'Ali. At first, the power struggles were able to conceal internal disunion, but this only produced a rotting division that continue even now. In the modern era, the country of Iraq is an example of it. Minority Sunnis ruled and persecuted Shiites under the government of Saddam Hussein.
The Sunni division is known for their Schools of jurisprudence. Ibn Hanbal also known as Ahmad was a leading Sunni Scholar theologian who was the founder of the Hanbali legal school. Hanabals believe that God had many names and attributes as mentions in the Koran. Hanbalis law is considered to be very traditional and strict and is mainly common in Saudi Arabia known for their fossil fuel. Of the four main Sunni legal schools, one of the largest and most widespread, after the Hanafis is the Shafii Legal School. It dates to the ninth century and bears the name of its founder, Muhammad' ibn idris al-shaFi'i. This school is based off some of the opinions of Muhammad's partners, but mostly from Al-Khulafa ar-Rashidun. The Hanafi School is named after the Iraqi scholar Abu Hanifa an-Nu 'man whose legal views were preserved primarily by his important followers; Abu Yusuf and Muhammad al-Shaybani. This is the most important and oldest among all Sunni Schools. It's known for putting greater value on reason and being more wide-ranging than the other three schools. Lastly, the School of Maliki gains from their work from Malik ibn Anas. The two main sources are that of the Muwaṭṭah and the Mudawwanah. The Muwattah is a collection of hadiths, which are regarded as sounds. The Mudawwanah is the collaborator work of Mālik's longtime student known as Ibn Qāsimand his mujtahid student also known as Saḥnūn.