Original sentence: Abu Bakr - First rightly guided caliph of the Sunnis.Ali ibn Abi Talib - Fourth and last rightly guided caliph, and considered the first imam by Shi'a Muslims.Haroon al-Rasheed - Abbasid caliph during whose reign Baghdad became the world's preeminent center of trade, learning, and culture.He was not accepted as a rightly guided caliph by the Sunni until the 10th century CE.Killed by rebels.Muawiya I - First Umayyad caliph.Subdued rebel tribes in the Ridda Wars.The Qur'an was compiled under his direction.Umar ibn Abd al-Aziz -  Umayyad caliph considered by some (mainly Sunnis) to be a fifth rightly guided caliph.Umar ibn al-Khattab - Second rightly guided caliph.Uthman ibn Affan - Third rightly guided caliph
Edited sentence: Abu Bakr - First Rightly Guided Caliph of the Sunnis.Al-Hassan ibn Ali ibn Abi talib - Second Shia Imam.Ali ibn Abi Talib - Fourth and last Rightly Guided Caliph.Ali was one of only two Shia Imams (whom the Shia consider the rightful heirs to the Caliphate) to actually hold the office (the other being his son Al-Hassan ibn Ali ibn Abi Talib, who abdicated six months after assuming office).Haroon al-Rasheed - Abbasid Caliph during whose reign Baghdad became the world's preeminent center of trade, learning, and culture.Muawiya I - First Umayyad Caliph.Much of his reign was fraught with internal conflict.The Quran was first compiled in the form of a book during his reign.Though technically a Rightly Guided Caliph, Hassan is not often mentioned as such due mostly to the extremely short and disputed nature of his reign.Umar ibn Abd al-Aziz -  Umayyad caliph considered by some (mainly Sunnis) to be a fifth Rightly Guided Caliph.Umar ibn al-Khattab - Second Rightly Guided Caliph.Uthman canonized the Quran.Uthman ibn Affan - Third Rightly Guided Caliph