In the 19th and 20th national convention of Kanyakubja Brahmins by Kanyakubja Mahati Sabha, in 1926 and 1927 respectively, Kanyakubja Brahmins whose different brahmin branches included Sanadhya, Pahadi, Jujhoutia, Saryupareen Brahmins, Chattisgadhi, Bhumihar Brahmins and differentBengali Brahmins.
"Kanyakubj Vanshavali" mentions five branches of Kanyakubja Brahmins as Saryupareen, Sanadhya, Bhumihar, Jujhautiya and Prakrit Kanaujia:
Saryupari Sanadhyashcha Bhumiharo Jijhoutayah
Prakritashcha Iti Panchabhedastasya Prakartitah
Sanadhya Samhita gives an account of the origin of the Sanadhya community. Lord Ramachandra of Ayodhya invited some Adi Gauda Brahmins to conduct a yajna. As dakshina he gave villages to 750 of them, who came to be called Sanadhya. They were engaged in tapa, thus came to be called Sanadhya
An alternative theory is that since they worship Lord Sun (or 'Surya') (Skt san), they are called Sanadhya. Sikh Guru Gobind Singh has mentioned that his ancestors once lived in the Sanadh region, this may have been the region from where the Sanadhya originated.
There have been genuine attempts to show the unity of Brahmins, but it was always to show that all the Brahmins were migrated and bifurcated from a "particular Brahmin". The point is missed that Brahmins as such were one original class which moved towards the East. It was a strict practice to safeguard the purity of the blood of the East-advancing front of Brahmins by taking girls from the west so that the East advancing front does not mingle up with the Nagas and other races which were pushed further east. Brahmins remember this practice even today to marry their daughters to the east and take girls from the west, and by doing so they preserved the purity throughout the Indo-Gangetic plains also called Gaudadesh. Later, when advancement to the east eventually completed, sticking up with locality was forced to check the continuous flux of Brahmins from the west. This was a wise step to control possibility of over-populating the firtile lands of the Ganges eastward.But, sadly, it resulted in a rigid and foolhardy localisation and division of the great width of Brahmins. They became almost myopic and lost their strength.
Sanadhya word carries two very ancient Sanskrit roots, in fact, of vedic antiquity. Sanah for a specific 'sacrifice'(Sanatana from the same root ~synonym) and aadhiyah or aarurha means 'incessantly engaged in', and also 'full of opulence' or 'rich in' or 'firmly walking (or mounted) foremost and ahead' on the path of penance. Hence those who possess opulence of Sanah sacrifice, or 'ahead in austerities'or 'mounted firmly, foremost and ahead of all, on the Tapascharya' were called sanadhyas in comparison to the Purohitas and Priest who lived in cities or villages.The term is non-local, and independent of region. It is associated with the Aaranyaka Brahmins, the forest dwellers, and therefore the much later classification into regional subclass into Panch Gauda and Panch Dravid does not include the forest dwellers. It is true that every Brahmin, wherever he may belong to,the glorious Saraswat of Kashmir, the matchless and graceful Kanyakubja, the pious and proud Sarayuparain, the brilliant and mystic Maithil, the holy and lofty Gauda or the one from great descent of panch Dravidas, has been a descendent of the original clans of Forest dwellers/or those engaged in austerities and penance.
The first story cited from the so called Sanadhya Samhita does not seem to be consistent. The composition of the Samhita does not seem to have any remote date in the history.During Rama's time, by any rate going prior to 600 BC, the time when division into subclasses as we presently know them, had not taken place. No question, then, arises for calling them to be a group of Adi gauda's participated in the yajna.However, the ground reality is that they remain non-distinct from Adi Gauda and do consider themselves the ascetic branch of Adi Gauda. In Rama's time there were only three occupations of Brahmins priests, Purohitas and Aranyaka Brahmins,some of them elevated to the level of Rishi. The Samahita seems to be quite recent or post-classification era, far down in time from the Valmiki Ramayana. Rama did meet Aranyaka Brahmins in the Valmiki Ramayana, and he did call them to be always engaged in Tapa and therefore were the Brahmins worthy of 'high reverence'. That is all.
The second hypothesis related to Guru Gobind Singh Sahib's ancestral village Sanadh, it again does not prove to be native place for sanadhyas and the name sanadhyas to be after this village.The opposite may be a possibility that the place came to be called Sanadh after the Sanadhyas.
Sanadhyas are a dominant section of north Indian Brahmins, most numerous in Gangetic 'Doaba' region and they touch the Kanaujias on the north west extending over central Rohilkhand, and the part of the upper central duab from Pilibhit to Gwalior. The boundary line runs from the northwest angle of Rampur through Richa, Jahanabad, Nawabganj, Barielly, Faridpur to the Ramganga, thence through Samilpur and the borders of Mehrabad, thence down the Ganges to the borders of Kanauj, thence up the Kali nadi to the western border of Alipurpatti, through Bhavgaon, Sij, Bibamau and down the Janumna to the junction of Chambel.
Sanadhya Brahmins make a triumvarate along with kanyakubj Brahmins and Bengali Brahmins in practicing the doctroine of nobility ; like biswa system of kanyakubj Brahmins and kuleen system of Bengali Brahmins, the sanadhyas rigourusly practice the 'allh' system to jeaously safeguard the purity of their blood. They are branch of Adi Gauda Brahmins, Rtviz of ashwmegh yajna performed by Lord Sri Rama and have matrimonial relations in their own fold and Adi Gauda Brahmins. They have matrimonial relations with kanyakubj Brahmins as well. It should be kept in mind that Lord Rama established 750 autonomous ashrams in the Doab region to institutionalize the otherwise unorganized spread of knowledgeable traditional Brahmins whom he had promised a safe living at the time of his exile. The adi gauda means the ancient undivided non-regionalised brahimins of the gangetic plains (i.e. the Adi gauda region) and not the Adi gauda sub-class of the present day classification in the strict sense of the word of that era, therefore, it encompasses all the best learned families of north Indian Brahmins.Further as the history goes this region faced invaders' cruelty and calamity and the institutional system faced greatest blows. Number of Vedic branches, shivaite schools, and grammarian and other rare traditional texts were lost. Yet, against all oddities Sanadhyas survived with their pure taste for knowledge though they were forced by the invaders to live in the fringes of un-fertile lands and ravines with little to support an average living.
However the Brahmins of different regions developed specialized understanding in the Brahmin pockets. The great clans of the Brahmins of Kanyakubja region were extraordinary in Raj-dharma and Nyay dhrama, the Saryuparain Brahmins were superb puritan of Ramashrayi school of Vaishnavas,standing high on the Epic and Puranas interpretaions and remain outstanding in the conduction, interpretation, and practice of religion, Maithils were great Shaktas with profound depth of tantrik taditions, Adigaudas, were precise Astrologers and adept Ayurvedic masters forming lofty Krishnashrayi school of Vaishnavas, Jijotiyas were the specilized vedic Karmkandi with perfection in Yagnik practices. Saraswatas excelled in Grammars and Yogik practices. Sanadhyas followed the diverse practices of Shaivite philosophy to Shakta tradition and so also thoroughly vaishnavism however keeping their eyes fixed on vedic and upanishadic abstract thinking. All this great width of Brahmins of Indo-gangetic plains flowed like thousand meadows through the second millennium of adversity to vedic religion.
Migration and infiltration of Sanadhya Brahmins into central India from the north took place after the fall of Marathas. In the beginning of the 19th century by 1820 AD families of Sanadhyas started to migrate to the Narmada valley extending from Mandla to Hoshangabad and so also into the Malwa from Vidisha to Ujjain and Indore. This migration was mostly from Bhind-Gwalior-Murena-Agra region where extensive Gully-Ravines were forming and penetrating into agriculture lands and converting these lands of Chambal-Yamuna belt into so called Badland Topography. The north-western MP i.e. Ratlam and Mansaur regions were infiltrated from southern Rajasthan. This migration may be corelateable with the deterioration of lands and family partitions. Those who opted to move to the fertile lands of MP were sufferers of family division and got ravenous part of the parental land on property divisions. The mass migration was accompanied by other people also belonging to Rajputs ( Chouhans and Sisodias), Kauravas, Jats, Gujjars, yadavas etc. Narsinghpur district. of Narmada valley has a good population of this assembly which is a facsimile representative of the Vraja-mandala includung part of Dhaulpur-Bharatpur and Gwalior region, wherefrom the migration had triggered. Remarkably, the Narmada valley was freed from Pindaries'Pindari' by 1820 by the Narmada Protection Force and from Thugs by 1842 by the great British officer Col. Sleeman. Thus Narmada valley became a safe and favourite place for settlement with its fertile soils. Apart from the Narmada region, migration took place from Gwalior-Jhansi-Urai area to the Sagar region of MP.