Brahmins in Palghat migrated at different times during the 14th to the 18th century, to Kerala. They came in vis the Palghat Gap (Walayar to Pollachi) on the western Ghats or via the Shencottah Pass near Quilon. Some did climb up the Cumbum Hills crossing over Munnar, Peermede etc. and settled in Kottayam, Haripad, Vaikom, Ambalapuzha etc. The Agraharams south of Trivandrum such as Nagerkoil, Vadiveswaram, Sucheendram etc, already existed as Chola territory.
It should also be noted that the Kings and Chieftains of Kerala were great admirers and respecters of Brahmins, even as a caste, and more as learned and religious persons. Their dily life routine also impressed, in fact, these have ben adopted by the Nair and other Sudra communities in Kerala. The food habits also got influenced. There was no alayalam language then as we now know it. It was all Tamil, in some form or the other, all bsed on Sanskrit words. Even to-day Malayalam is over eighty per cent Sanskrit!
The Brahmins came because of great employment opportunities in Kerala, as teachers, religious facilitators, pundits, accountants, musicians and music teachers, ministerial helpers etc. They were encouraged to come in by allurements of free food, housing, grant of lands, cash gifts, recognition at the highest levels, titles etc. It should be noted that Brahmins were famous as honest and reliable people,
The first batch of migrants to the Palghat region came from Trichy District and around, primarily the then Pandya Kingdom. My own family came from Kandarmanickam Village, near Chettinadu, I think. They settled down in Old Kalpathy, establishing the first agraharam, parallel to the Kalpathy River and close on its bank. They were all Vadamas, worshippers of Krishna in their native village. So, they founded the Lakshminarayana Temple in Old Kalpathy. The next batch was mostly Brahacharanams, Vedic scholars and priests. Their number was large and they founded the adjoining New Kalpathy Agraharam, also alongside the river bank. This is the longest village among Agraharams, almost 180 houses.
The succeeding batches came and settled on river banks in Govindarajapuram, Vaidhyanathapuram, Chockanathapuram, Mukkai, all on the banks of the same river. It will be seen that the availability of the river for their morning baths was an essential part of their life-routine, hence the choice of their settlement. These villages got the same names as their original villages in Tamil Nadu and the temple dieties were also the same. My views will be confirmed when you see the Google map of Kalpathy villages.
By the time the Pallipuram, Nurani and Tirunellai (also Sekharipuram) people migrated, there was no place available adjacent to the Kalpathy River, so they settled wherever they could. Tirunellai people came from Tirunelveli (which is also called Thirunellai in Tamil) and chose the location of their village because of its contiguity o the Yakkara Kannadi river. They came to these villages from Srirangam, Conjeevaram, Srivalliputhur and other centres of Vaishnavism. They were used to the pure Vaishnavite traditions of living, such as Namam, names of individuals, worship of dieties etc. Basically, they are Vadama Smartha brahmins, who worship all Gods, but primarily in the Vishnu aspect. The Thirunellai people also woprship Sankarshana, an aspect of Vishnu. All these are external, since they “wanted to be Romans, while in Rome”. They also owe allegiance to the Jeer in Srirangam or other Vaishnavite Acharyas . Our Sankaracharyas are not welcome in these villages, even to-day. Mostly, they marry only between these villages, until 50 years ago.This has changed completely, now.
Pallipuram name itself indicates, the existence of Moslem mosque, and Nurani is a Moslem name, Sekharipuram is named after Sekhari Varma, the then Chieftain of Palghat, who welcomed them as settlers.