not sure..
i think Shia holds Caliph Ali, his sons (Hassan and Hussein) and wife, Fatimah (also the Prophet (peace be upon him)'s daughter) as very important people, which they are, NO DOUBT, but i think they take it too far...

im saying "they" because I'm not Shia, but i also decided that i wouldnt be called "sunni" either. im just muslim, trying to be mu'min, following the Qur'an and the Prophet and the unbiased explanations of ahadiths as best i can. <--This might be a longer explanation then "im sunni/shia/salaf" but I think its worth every single seconds spend on explaining.

if we start calling each other names, thats when we start breaking apart and thats how bad stuff gets in, science-cy comparaison..--> "how to increase the rate of reaction? increase surface area" Muslims are the limestone and the people who want to divide and rule us is the hydrochloric acid. if we start dividing ourselves, we'll be gone in seconds.

If any Shia do not like my explaining, please forgive me, i do not mean to offend anyone but i am also trying to gain knowledge by putting down what i already know or think i know, if you know better, please, feel free to correct me.

~`^
after the demise of the prophet (pbuh) we know the four caliphss that came after him. The last was Hazrat Ali Bin Talib (radiy Allah u taala anhu) and some people believed that he should have been the first calipha.
the earliest explicit dispersion of false info regarding the leadership of Hazrat Ali is connected with Abdullah Ibn Saba.

He became a muslim earlier on but believed that the divine spirit which was embedded within the prophet (pbuh) transfered to Hazrat Ali (radiy Allah u taala anhu).
a lot of non arab muslims (mainly persians) were attracted to this concept and so these people seperated themselves from the mainstream of the Muslim Ummah ans became a large sect known as we do today Shi'as, they also refer themselves as Ahlal al Bayt (people of the house).

got info from the girls dalrum where i live

That is rather simplistic IMO.

People in Persia and Egypt were used to hereditary empires and such a thing made sense to them. More, there were people who legitimately thought that hadhrat Ali (ra) should have been the caliph.

The original disputes were political and were amicable too. They even diseared later but were reopened with the martyrdom of Imam Hussain (ra) and eventually over time also took on a religious perspective - this may (or may not) have been influenced/led by the person you mentioned but putting everything down to one person may be over simplifying things.

Theories like the Jew convert to Islam, Abdullah ibn Saba, or Persian influences are challenged by modern scholars, some of whom have even disputed the existence of Abdullah ibn Saba.

Two credible theories exist for the origins of shia'ism:

- The first is based on the displeasure of Ali and his supporters about Abu Bakr's elections (recorded by Muslim historians including Tabari). Thus early in the history of Islam the Shia were a political faction that supported caliphate of Ali and later his descendants. They gradually developed into a religious movement.

- The second theory emphasizes different interpretations of Islam which led to different understandings about the role of caliphs and ulamas.
The scholar Hosain argues "...there were exoteric [Zaheri] and esoteric [Bateni] interpretations from the very beginning, from which developed the schools (madhhab) of the Sharia and Sufism in the Sunni world, there also had to be an interpretation of Islam, which would combine these elements in a single whole. This possibility was realized in Shi'ism, for which the Imam is the person in whom these two aspects of traditional authority are united and in whom the religious life is marked by a sense of tragedy and martyrdom... Hence the question which arose was not so much who should be the successor of Muhammad as what the function and qualifications of such a person would be."