Muawia Bin Abi Sufiyan(also Muawia I) can easily be regarded as the main figure responsible for sectarian among Muslims today.
I will give a detailed view on Muawia as a neutral Muslim, then will also briefly mention the stance of three groups mentioned in the question.
As a neutral Muslim, I must say Muawia Bin Abi Sufiyan was a criminal who broke the powerful Islamic system of caliphate and replaced it the Byzantine styled absolute monarchy.
Muawia and his family became Muslim when Makkah was conquered by the Holy Prophet PBUH when they had no other option but to accept Islam.
Muawia’s main appearance in Islamic history starts in the later reign of Caliph Umar. When Muawia’s brother Yazeed Bin Abi Sufiyan the governor of Damascus was martyred, Muawia succeeded him as governor. It was Muawia’s good luck that he was appointed governor of Damascus by Caliph Umar in his last year caliphate otherwise after four years of governance he would have been dismissed by the Caliph. After Caliph Umar’s martyrdom, Usman Bin Affan became the Caliph who a relative of Muawia, both being from the same clan of Banu Umayya. Caliph Usman extended Muawia’s domains by appointing him as the governor of entire Syria. From then on started Muawia’s anti-Islamic policies. For example, legalizing Usury, having the lifestyle of Byzantine emperors, disregarding Islamic rules and regulations, giving preference to his own qiyas(analogy) to Prophetic traditions, etc. By the end of Usman’s caliphate, Muawia had became a very powerful governor with a large army under his command. When Caliph was martyred by the rebels , Muawia demanded for Qisas for Usman from the new Caliph Maula Ali. Since the murderers of Usman consisted of a large group of people it was totally impossible to punish them right away so Caliph Maula Ali requested Muawia to have patience and when his caliphate will become stable the Caliph himself will punish the murderers of the late Caliph. But Muawia insisted on taking revenge as soon as possible which was impossible for Caliph Ali. (One point to be noted here is that Muawia was given order of dismissal from Caliph Ali but Muawia replied that he had not recognized Ali as the caliph and he was still demanding Qisas from Ali.) Muawia had no real interest in punishing the murderers instead he wanted to gain political influence in the presence of a Rightly Guided Caliph. Thus Muawia started a series of mischievousness to unstablize Ali’s caliphate. He mustered an army to battle the Caliph. Caliph Ali also gathered an army and marched towards Muawia to defeat him. Both the armies gathered on the ground of Siffeen. Ali’s army having an upler hand were on the verge of totally overhauling Muawia and his army, but on the advice of Muawia’s lieutenant Amr Bin Aas, Muawia ordered his army to put scrolls of Quran on their lances from getting being defeated. Hence his trick proved a success for Muawia. He saved his army from total annihilation. Later on, he continued his policies of aggression against Ali until his martyrdom.
After Ali’s martydom, People of Syria recognized Muawia as the new leader but People of Iraq appointed Ali’s son Hassan as the new caliph. Muawia also started policies of aggression against Hassan Bin Ali. After much bloodshed, Muawia offered peace to Hassan Bin Ali. Hassan agreed to conduct peace on some conditions. Some of conditions are as follows:
- Muawia will rule in accordance with Quran, sunnah of the Holy Prophet PBUH and that of the previous Rightly Guided Caliphs.
- Muawia will spot the cursing of Ali from mimbars of Masajid in his domains.
- Muawia will stop all policies of aggression against Ali’s supporters and his lovers.
- Muawia will continue to give Ahle Bayt Alahim Assalam Khums as commanded in the Holy Quran.
Except the last condition, Muawia broke all the conditions of peace treaty he signed with Hassan.
After Hassan resigned, the period of Rightly Guided Caliphate came to an end as prophesied by the Holy Prophet PBUH that Caliphate will remain for 30 years and when Hassan Bin Ali resigned thoae 30 years completed hence the reign of Rightly Guided Caliphate ended. From then on, Muslims dynastic rule started. Muawia was the first Muslim king.
When we discuss about Muawia’s reign, we only see terrorism, injustice, worse behavior towards Ahle Bayt Alaihim Assalam, etc.
Muawia instituted the innovation of cursing the Rightly Guided Caliph Maula Ali from mimbars on Fridays. The governors were given special orders to curse Ali. Saad Bin Abi Waqqas and Sahl Ibn Saad Al-Saadi were also instructed to curse Ali but they said a straight away no. They argued that how could they a person who was blessed by Prophet PBUH by so many virtues? But unfortunately many elderly individuals such as Mugheera Ibn Shuba started cursing Ali from mimbars. Moreover, Muawia authorized the public treasury for his personal use. He also commanded his followers to loot innocent people and to kill them unjustly. Muawia is also credited for poisoning Hassan Bin Ali through his wife Jada bint Ashas.
This was only a brief introduction of Muawia’s character as per authentic ahadith and narrations. I can give reference of any event mentioned in this paragraph on demand.
Now briefly discussing Sunni view on Muawia:-
Early Sunnis were of the view that Maula Ali was on truth against his opponents and Muawia was a rebel, fasiq and cruel person. But later, when Shia enemity flourished among Sunnis, they started to defend Muawia’s character by labelling them under the name of Ijtehadi Khata. From then on, prejudice gained influence among Sunnis and they diluted Ali’s importance and started defending Muawia.
On point to be note is that Sunnis regard Ali as the rightful one and also regard Muawia was on mistake(well a very huge mistake) and they forbade cursing and doing takfir of Muawia.
Salafi stance on Muawia:-
Early Salafi scholarship had same view regarding Muawia as that of Sunnis. Even there were even some hard core Salafis who openly refuted Muawia’s policies for e.g Wahid Uz Zaman Salafi.
But later, this sect became official defenders of Muawia and haters of Maula Ali. They wrote hundreds of books in praise of Muawia and started refuting narrations in praise of Ali to dilute Ali’s importance in sight of their followers.
Shia view on Muawia:-
Early Shia view was similar to early Sunni view but later on they exaggerated in their refutation of Muawia. The started cursing Muawia as Muawia used to curse Ali. In short, they adopted the very same innovation which Muawia started to degrade Ali. Shias don’t consider Muawia to be a Muslim.