The ground was laid when the Pallavas deemed Kanchi their capital city in the 6th century. Then came the Cholas, the Pandyas, the Hoysalas, the Vijayanagar kings, the Nayaks and the Carnatic kings. The list goes on. With each successive kingdom, Kanchi’s place as a city to invade, conquer, fortify, beautify and contribute to, grew from strength to strength. Each successive kingdom brought patronage for the arts.
And thus we come to the reason why the weavers came to this city. In one line, it was to create sarees for the gods.
With so many temples, there was a desire for royal cloth for the gods– first from cotton and later from silk. The kings and priests who venerated these gods needed weavers. So they came from nearby towns and states: the Padma Saaliyars from Andhra, the Devangas from Karnataka, the Sengunthars from Tamilnadu, the Saurashtras from Gujarat by way of Madurai and Thanjavur. All were drawn by the prospect of creating value to the kings by way of weaving cloth for the gods. By the prospect of wealth.
You see, at the end of the day, it is all economics, really. And so it was in Kanchi.