Iraqi Biradri (Arabic: ﺁلعرﺁقي برﺁدرى) is a Sunni Muslim caste, and is found chiefly in Ghazipur, Azamgarh, Ballia, Deoria and Gorakhpur districts of the Eastern Uttar Pradesh (U.P). Iraqi Biradri is also referred to as Iraqi Shaikhs, Iraqi Sayyids.
Iraqi biradri is a descendant population of the immigrants from the country of Iraq. Recent facts argue that their ancestors were the immediate descendants of Sayyid Masud Al Hussaini and his poorly defined retinue, all recent immigrants from Iraq. Sayyid Masud Al Hussaini successfully extended Ghazipur area under Delhi Sultanate, settling with his family in the newly conquered city during the Mamluk Sultan Firoz Shah Tughlaq circa 1330.  
As a result Iraqi Biradri is known to settle in14th century in Ghazipur roughly with an origin 700 years ago. Following an initial growth period of a couple of centuries in Ghazipur chiefly in towns among others Nonahra, Gangauli, and Kasimabad, a population dispersal took place in neighboring districts mainly Azamgarh, Ballia, Deoria (Gprakhpur) and some other places. Their ancestors as old as 300 years or more are very well identified in many towns/villages of the aforementioned districts including Ghazipur in the form of distinct family trees. 
With reference to the Sunni Muslim ‘Iraqi Biradri’, more than a century earlier, in relation to another Muslim caste from the converted Hindu Kalals (a class of wholly muslim caste after the conversion) or simply ‘Kalal Iraqis’ in the United Provinces (or U.P.), a fallacy was created from the work of the British colonial civil administrators and others as published elsewhere. Those authors did not attempt to distinguish the two populations. In fact, they grouped Iraqi Biradri together with the Kalal Iraqis who actually dealt with the business of ‘Araq’ or spirituous liquor in the past as ‘Araquis’ in U.P. (also in Bihar), assuming that the claim of Iraqi Biradri to be immigrants of the country Iraq was fictitious. It is not a correct way to characterize them in one group without taking into account all the properties pointed out in some of the papers, such as political/cultural practices, place and origin, with respect to each population (also the phylogenetic Y-DNA trees).
It is described clearly in the above papers that the "Kalal Iraqis" reside mainly In Mirzapur district, are linked with indigenous roots in India i.e. Hindu rituals are noted in marriage/divorce activities; they practice hypergamy and they are under the caste Panchayat rule. By contrast, the descendant families under "Iraqi Biradri" are identified distinctly as follows: bulk of them reside mainly at places i.e. Ghazipur, Ballia, Deoria and Gorakhpur (not Mirzapur) in the Eastern U.P.; time of their domicile in India is relatively recent -Hindu rituals/traditions do not exist in marriages or divorces; they are not under caste Panchayat rule; their combined patrilineal Y-DNA phylogenetic trees are possibly unique, see below. The failure to distinguish "Iraqi Biradri" from others earlier in the above publications may be due to a deliberate attempt or a fortuitous omission by the authors, but it alters the characteristics of the Sunni "Iraqi Biradri" as a caste with foreign roots to that of a caste with no foreign roots - a low status.
Consistent with a past record of enterprising Iraqi Biradri in U.P, majority of the them were engaged in manufacturing business/trades of goods during the 20th century, albeit a small number acted as money lenders, Zamindars with and without cultivating lands in villages in some districts like Ballia. Examples in the recent past included: ownerships of Sugar Mills in North Eastern U.P., North Western Bihar, Textile mills in Kolkata and leather tanneries in Kanpur, Hotel business in Nepal. The Iraqi Biradri who live in big towns in India continue to do businesses that include Leather Industry in Kanpur, Kolkata, Chennai, Hotel and tourism Business in Nepal. Otherwise the majority has been involved in retail business/small manufacturing business in places of residence. The educated members of the Biradri , few in number, work as medical doctors, teachers, engineers in India and abroad.
The present population size of Iraqi Biradri may fall in the category of small ethnic groups in India. The basal population still lives in towns of its origin and other nearby towns in Ghazipur, Ballia, Deoria/Gorakhpur, Mau, Azamgarh in Eastern U.P. against the continuous flow of population out of those towns during the last 600-700 years. The people speak Urdu and local Bhojpuri, Awadhi dialects. The grasp on Arabic/Persian used to be strong in most families 50-100 years ago.
Iraqi Biradri practices endogamy within its own population; consanguineous i.e. first cousin/second cousin marriages are allowed. Genetic study on Y-chromosome SNP and Y-DNA STR in a large sample of extant Biradri needs to be done. However, a few Y-DNA SNP phylogenetic tree results from the male members of the Biradri are known between them.The members are second to 3rd cousins based on autosomal DNA overlapping noted in the DNA relative section of the result by 23andMe. After confirming each other as members of the Biradri, our Y-DNA SNP haplogroup include: Indo-European M198(R1a1a)-->Z93/Z94→Y40→M560; M198(R1a1a)-->Z93/Z94→L657→Y6;;Middle Eastern J2-M172→J2b M102→J2 b2-J-M241;and Arab J1-M267→J1a CTS5368/Z2215.