When did the division between Sunni and Shiite muslims occur?

Answer 1

On the selection of prophet Muhammad (PBUH) successor in year 632 AD.

Muslims just got divided on the way the successor of the prophet (after his death) should be. Muslims elected Abou Bakr to be the first Caliph after prophet Muhammad (PBUH) death. However, some Muslims believed that the successor should be from the family of the prophet and hence should Ali Ibn Abou Taleb (the prophet cousin and husband of his daughter). However, after the election of AbouBakr, they joined the majority and even Ali Ibn Abou Taleb (God be pleased with him) supported the elected Caliph. The same scenario was repeated after election of Omar Ibn Alkhattab as the second Caliph and Othman Ibn Affan as the third Caliph. Ali Ibn Abou Taleb was then elected as the fourth Caliph.

However, Sunnis and Shiites are just two Islamic schools that differ in minor issues.The outsiders are trying to feed up assumed differences and conflicts between Muslim groups to gain control on Muslim countries and on their resources. The two main groups are Sunnis and Shiites. Both groups agree upon basic Islam pillars, believe in same and only version of Quran, believe and follow the sunnah of same prophet (PBUH), pray to same direction (facing Kaba in Makkah or Mecca in Saudi Arabia, go to same places on pilgrimage (or Hajj), and adhere to same Islam morals and ritual worships. They only differ on some side issues that are not critical.

Answrer2

when prophet Muhammad SAWW died and Ali a.s was at funeral of prophet SAWW an leader was elected and it was start of division between supporters of Ali a.s. and supporter of elected ruler.

They just got divided on the way the successor of the prophet (after his death) should be. some of top Arab tribe bosses at Saqifeh elected Abou Bakr to be the first Caliph after prophet Muhammad (PBUH) death and other Muslims were forced and even killed (for example سعد ابن عباده Saad Ib Ebadeh) to accept this ruler. Some like Ali a.s., Salman, Abuzar, Miqdad, Bilal,... disagreed this election. they believed that the successor should be Ali a.s. because God selected him as leader and not because he is relative of prophet SAWW. However, after the election of AbouBakr, they did not fight for power and Ali a.s helped the elected Caliph for survive of real Islam and to big enemies like Roman and Persian empires can not destroy Islam using civil war of Muslims. and always declared his disagreement with this election bu did not made civil war for power. The same scenario was repeated after election of Umar as the second Caliph by will of Abubakr and Othman as the third Caliph by election in a 6 persons meeting. when Muslims killed Uthman for his corruptions Ali a.s. was then elected as the fourth Caliph by majority of Muslims while he was not interested in power.

However, Sunnis and Shiites are two Islamic schools that differ in major (pillars of Islam) and minor issues. The world Imperialists know Islam is truth and if people know this they will lost power. so they try to make wars between Muslim groups to gain control on Muslim countries and on their resources. for example they bomb a shia mosque and tell in media that sunni did it and so on. The two main groups are Sunnis and Shiites. Both groups agree upon basic Islam pillars(unless Imamat (Islamic rules for political leadership)) and believe in same and only version of Quran and follow the sunnah of same prophet (PBUH), pray to same direction (facing Kaba in Makkah or Mecca in Saudi Arabia, go to same places on pilgrimage (or Hajj), and adhere to same Islam morals and ritual worships. Thier main differ is in Imamat.shia beleives based on Quran and Islam the only one who has the right to elect the leader is God and Muslims do not have such a right in Islam.