Years back I asked my grandpa (may he rest in peace and may Allah shower all His blessings upon him) who are we and where we come from. He gave me a book by Ali Asghar Chaudhry entitled Tareekh-e-Araiyan published by Ilmi Kitab Khana, Urdu Bazaar. Its a 7"x10", 627 paged massive book. I never read it completely but it was through it that I came to know my history :) After describing the histroy, this book enlists in detail the Arain families from all over Pakistan and in the end from India. Among the families of Lahore the book names my great great grand uncle and my great great grand father which my grandpa had marked with a pen. (Thank you grandpa, I wish you were here and I could get more from you). I describe it briefly below.
In the Ummayad Dynasty (660-750 AD) there was a city, Areeha which lied on the road from Damascus to Jerusalem (now in modern Israel, close to the Dead Sea). For the protection of Damascus this city had geographical importance. Keeping in mind its importance, such people were given lands in Areeha who belonged to the superior families of Banu Ummayad or who were loyal to the Ummayads. These people were natural fighters, physically the fittest. Their ancestors were adept in wars. Not only they were skilled warriors but they were also good at agriculture. They cultivated the land of Areeha and it flourished. (Areeha is also called Jerico or Yareeho. Areeha is from Areeh which means aroma, Areeha means garden)
When Hajjaj Bin Yousaf decided to send his men to conquer Sindh, six thousand best soldiers were selected from Areeha along with smaller number of soldiers from other parts of Syria. They entered South Asia under the leadership of Muhammad Bin Qasim, defeated Raja Dahir, conquered many parts and introduced Islam in the region. After the death of Hajjaj Bin Yousaf and Caliph Abdul Malik, Caliph Suleman came to power. He had some family conflicts with Hajjaj Bin Yousaf. The new governor took revenge against all who were close to Hajjaj. Suleman owed political support to opponents of Hajjaj and so recalled Hajjaj's successful general Qasim while his men were forced to stay back.
Those who stayed never went back to the present day. Accoding to their origin they were Areehai which later took the form of Arain. After Qasim's return they chose a new leader, continued their attacks on other regions, established their governments in Sindh and Multan regions. Their families started growing in the region. Later a large part of the armies of Mehmood of Ghazni, Muhammad Ghori, Sher Shah Suri and the Mughal Emperors comprised of Arain people.
There are however other theories of the origin of Arain which the book refutes by giving proof. It may not have any significance today but for the sheer knowledge of it, there are four main rankings (not sub-castes) which refer to the wealth held by the Arain namely Mian, Malik, Chaudary, and Mehar. The rankings among Arain are not birthrights (such as those among other castes) and one can freely ascend/descend according to changes in personal wealth. Many gotras or sub-clans of the Arains bear names that indicate soldiering as an occupation. For example: Ramay (archers), Rattay (bloody, red, ferocious fighters), Ramday (red -eyed soldiers), Jatalay (victors), Qutub Shahi: (soldiers or their offspring who accompanied Qutubuddin Aibak), Bahalwan (driver of a chariot) and Bhutto (dwellers of high places).
A study by the Pakistan Journal of Medical Sciences on blood types of the major ethnicities in the Punjab showed that O is the most common blood group (among all ethnicities), except among the Arain where B is most common.
Proud to be an Arain :-D