Prevented Prophet Mohammed from writing his will in last hours.
Usurped Imam Ali's (Prophet's cousin) right for caliphate, made Abu Bakr 1st Caliph.
Assaulted Fatima Zahra (Prophet's daughter), she later miscarried her baby and passed away.
Forbade legal rulings in Islam, also, innovated illegal rulings in Islam.
Ran away from battle of Uhad and Hunain.
Had questioned prophet-hood of Prophet Mohammed at event of Hudaibiyah truce.
2) Abu Bakr son of Abu Quhafa
Usurped Imam Ali's (Prophet's cousin) right for caliphate, became 1st Caliph.
Snatched Fatima Zahra's (Prophet's daughter) properties of Fidak and Khaybar gardens, citing lame excuses. Fatima Zahra openly declared her anger with Abu Bakr.Wrote a will and declared Umar s/o Khattab to be next caliph, without any authority to do so, remember Prophet Mohammed himself was prevented to write a will.
3) Uthman son of Affaan
Had ran away from Uhad battle, defying Prophet Mohammed's clear orders.
Was named in committee to propose next caliph by Umar s/o Khattab, agreed to terms and conditions to become caliph by other members, terms and conditions had no Qur'anic sanctions, thus, Imam Ali had denied the terms.
Cancelled the orders of Prophet Mohammed for life extermination from Madina for Marwan s/o Hakam (Uthman's son in law) and his father, allowed both of them re-entry in Madina.
Exterminated Abu Darr Ghiffari, a loyal companion (Sahabi) of Prophet Mohammed from Madina, he died due to starvation in nearby desert of Rabada.
Made Ommayyads (his family clan) chiefs, governors, and jurists, turned political power into their family monopoly.
4) Aisha, widow of Prophet Mohammed, daughter of Abu Bakr
Received warnings for divorce from Prophet Mohammed in Quran (Surah Tahrim).
Neglected the Quranic orders to live seclusive life by undertaking pilgrimage to Makka after Prophet Mohammed.
Declared open war on Imam Ali's caliphate and accused him of Uthman's murder.
She herself went at battle-field in Basra, Iraq, fought battle of Jamal and lost the battle, however, she was freely sent back to Madina by Imam Ali.
5) Hafsa, widow of Prophet Mohammed, daughter of Umar
Received warnings for divorce from Prophet Mohammed in Quran (Surah Tahrim).
6) Abu Sufyan son of Harb
Staunchest enemy of Prophet Mohammed before converting to Islam, yet his actions remained hypocritic.
Himself being Ommayyad leader, played important role in power monopoly during Uthman's reign.
7) Hinda wife of Abu Sufyan, daughter of Utba
Stanchest enemy of Prophet Mohammed prior to her conversion, Prophet Mohammed ordered her never to come in front of him; even after her conversion.
She was the one who had cannibalised Hamza (Prophet's uncle) during Uhad battle, she had slit open and chewed liver of Hamza.
8) Mauwiya, son of Abu Sufyan and Hinda, father of Yazid
Had converted to Islam only after Abu Sufyan's pressure, but remained hypocritic.
Accused Imam Ali of murder of Uthman (his cousin, 3rd caliph)
Rejected the decision to make Imam Ali as 4th Caliph, broke away from main stream Islam.
Declared war on Imam Ali and Imam Ali's caliphate, fought battles with him, ie. Siffin.
Murdered numerous Companions (Sahaba) of Prophet Mohammed, namely: Ammar s/o Yasir, Mohammed s/o Abu Bakr (Imam Ali's adopted son).
Murdered 2nd Imam Hasan (Prophet's grandson) after truce through Imam Hasan's wife.
Broke truce by nominating his son Yazid as next caliph, turned Islamic political power into Ommayyad dynasty.
Desecrated the grave of Hamza (Prophet's uncle) in Uhad, citing reasons of irrigation.
Initiated the custom of public cursing of Imam Ali, even from pulpit of mosque during Friday sermons, the cursing was stopped later by Umar (another) s/o Abdullah during his caliphate after many years.
9) Abdur Rehman son of Auf
Had been member of committee to propose next caliph as declared in illegal will of Umar.
Put terms and conditions on Imam Ali that if they made him 3rd caliph; he will work under their pleasure and would take their opinions in all matters, Imam Ali denied those terms.
Later, put those terms and conditions to Uthman, he agreed and was made 3rd caliph, they made Islam as their monopoly, which resulted in riots, and later murder of Uthman.
10) Abu Musa Ash'ari
During truce offered by Mauwiya to Imam Ali after battle of Siffin, he was sent as arbitrator from Imam Ali's side.
Imam Ali himself never appointed him as his arbitrator, Imam Ali recomended either Abdullah s/o Abbas (Prophet's another cousin) or Malik Ashtar, both were rejected by public.
When Imam Ali found opposition for his choice, he isolated himself from the matter, and Abu Musa Ash'ari was sent as his arbitrator without his consent.
Beguiled by Amr s/o A'as, he openly rejected the authority of Imam Ali on caliphate, and gave baseless declaration that he impeached Imam Ali from caliphate.
11) Talha son of Obaidullah
Had been member of committee to chose 3rd caliph in illegal will of Umar s/o Khattab, tried his best to prevent Imam Ali to be taken as first priority by committee.
Later, accused Imam Ali for murder of Uthman.
Declared open war on Imam Ali, fought battle of Jamal, Basra, Iraq along with Aisha (Prophet's widow).
Sensing defeat tried to ran away from battle field but was killed by Marwan s/o Hakam his own ally, while running.
12) Abu Obaidah son of Jarraah
Abu Obaidah was at Saqifa council when Abu Bakr was chosen as first caliph, he insisted that he be made 1st Caliph, but lost the election to Abu Bakr.
13) Mughaira son of Shu'ba
He practiced open opposition for Imam Ali during reign of Uthman.
He circulated illogical Hadiths (Narrations like Peeing while standing, purchasing onion to get Paradise etc).
14) Abu Huraira
His status is similar to Mughaira, he too circulated illogical hadith (narrations about Prophet Moses' nudity etc)
Took active side of Mauwiya, since he was poor and Mauwiya funded him as and when the latter desired.
15) Anas son of Malik
Openly opposed Imam Ali
Circulated Hadith (narrations) which nullified position of Family members of Prophet Mohammed and Imam Ali in particular.
16) Wahshi son of Harb
Henchmen of Hinda and Abu Sufyan, to kill Hamza (Prophet's uncle).
17) Amr son of Aa's
Worst politician, played barbaric politics for Mauwiya
Person behind the idea to tie Qur'an on spear to stop army of Imam Ali from marching ahead, resulted in blasphemy and riots.
Chief ally of Mauwiya during his war against Imam Ali.
Main co-accused behind murder of prominent companions (Sahaba) like: Mohammed s/o Abu Bakr (Imam Ali's adopted son) and Malik Ashtar in Egypt.
18) Khalid son of Walid
Murdered a companion (Sahaba) Malik s/o Nuwaira in Najd area when latter denied his vote in favour of Abu Bakr as 1st Caliph. Malik s/o Nuwaira was made governor of Najd by Prophet Mohammed himself.
Raped Malik's s/o Nuwaira wife 'Laila', after her husband's murder.
Member of the gang that assaulted the house of Imam Ali and in which Fatima Zahra the daughter of Prophet Mohammed was brutally wounded, miscarried her baby and later got martyred
19) Abdullah son of Umar
Son of 2nd Caliph Umar, declared his isolation from politics yet gave unconditional allegiance to Yazid's governor in favour of Yazid.
20) Marwaan son of Hakam
Son in law of 3rd Caliph Uthman, Marwan was exterminated by Prophet Mohammed himself from Madina for lifetime.
He mocked Prophet Mohammed on several occasions.
Uthman, when he became 3rd caliph cancelled the orders of Prophet Mohammed and allowed him re-entry in Madina
Had been chief ally of Uthman during Uthman's reign.
Accused Imam Ali for murder of Uthman.
Declared open war on Imam Ali.
Remained chief enemy of Prophet's family.
After Yazid's death declared himself caliph, and started Marwanide branch of Ommayad caliphate.
21) Hakam son of Waail
Father of Marwan, he too was exterminated for lifetime from Madina by Prophet Mohammed himself.
Uthman his son's father in law allowed him re-entry in Madina, cancelling orders of Prophet Mohammed, when Uthman became 3rd caliph.
22) Yazid son of Mauwiya
Chief person behind the tragedy of Karbala, wherein, Grandson of Prophet Mohammed 'Husain' was mercilessly martyred along with 71 other men of 3rd Imam Husain, including a six month baby of Imam Husain.
Practiced worst form of cruelty during his reign.
Had sent an army to attack holy cities of Makka and Madina, Ka'ba ( House of Allah) was attacked with catapult, both sanctuaries (Haramain) were desecrated.
Imprisoned Granddaughters of Prophet Mohammed along with other women and children, after arresting them when Imam Husain and his men were martyred in Karbala.
Declared openly that Islam was a folly, and rejoiced that he had taken revenge for loss of his forefathers at hand of Prophet Mohammed in battle of Badr.
23) Yazid son of Abu Sufyan
Was nominated was governor of Syria by Umar s/o Khattab, but he died and he was replaced by Mauwiya his brother by Umar the 2nd Caliph.
24) Ziyad son of Abu Sufyan
Chief member of Ommayyad power monopoly, enemy of clan of Prophet Mohammed.
25) Obaidullah son of Ziyad (Ibn Marjaana)
Son of Ziyad and cousin of Yazid, he was appointed governor of Kufa by Yazid with command to deal with Husain (Prophet's grandson).
Ordered the killing of 'Muslim s/o Aqeel' cousin of 3rd Imam Husain.
Murdered numerous companions (Sahaba) in Kufa during his reign of terror.
Haani s/o Urwa, Muslim s/o Aqeel, Meesam Teemar were murdered as they were chief supporters of 3rd Imam Husain. Haani was shot with spears, Muslim was thrown from castle tower and Meesam was crucified.
He undertook the command of Battle of Karbala.
It was he who imprisoned Granddaughters of Prophet Mohammed along with other ladies, assaulted them, and later sent them to Yazid in Damascus as prisoners.
26) Ka'ab Al Ahbar
Imam Ali declared him a hypocrite and a liar, he had converted to Islam to acquire power.
Umar s/o Khattab 2nd Caliph made him his chief adviser.
After Umar's death he went and served at court of Mauwiya
27) Umar son of Sa'ad
Commander of the army which mercilessly slaughtered the family members of Prophet Mohammed, in Karbala.
Committed worst atrocities on 3rd Imam Husain's (Prophet's grandson) camp.
Declared that he is the first person to fire the first shot at Husain's camp and thus officially starting the battle of Karbala.
28) Walid son of Uqba
Step brother of 3rd Caliph Uthman, who nominated him as his governor to Kufa.
Openly, practised drinking, and thereby altered prayers, was later called back by Uthman.
Thereafter, served at court of Mauwiya.
Shia Islam is silent on following two persons, their statuses are ambiguous. Thus, high level Shia opinion is silent on their statuses. God knows best in their regards, one can't make a complete negative opinion for the following two persons:
1) Zubair son of Awwam
Fought with Imam Ali, but showed remorse right amidst battle, left the battle, but was killed by his former ally Talha s/o Obaidullah. God knows best in regards to Zubair, Shia Islam is thus silent on his status.
2) Sa'ad son of Abu Waqqas
Didn't paid allegiance to Imam Ali as 4th Caliph, but openly rejected Mauwiya's proposal with regards to cursing Imam Ali, and waging war on him. Neither favoured nor opposed Imam Ali, but remained isolated. God knows best in regards to Sa'ad, Shia Islam is thus silent on his status.
Note : All these historical facts could be easily proved from Shia and Sunni Books