[3] The clan traditionally held sway over the port of Vizhinjam, the fertile region of Nanjinad, and southern parts of the spice-producing Western Ghat mountains.

[4][1] Greek geographer Claudius Ptolemy (2nd century CE) described the "Aioi" territory as extending from the Baris (Pamba) to Cape Comorin (Kanyakumari).

[11] According to P. Shungoonny Menon (1878), the Ay family were classified as Pure Kshatriyas (by the Nambudiri Brahmins) and were related to the Mushika dynasty of northern Kerala.

[1] Originally the whole region of Venad (Vel+natu = the country of the Vel people, related to the Ay family) was part of the larger Ay-Vel territory.

[14] In c. 765 CE, Pandya king Jatila Paranthaka/Nedum "Maran" Chadayan Varaguna I (r. 765–815 CE) sacked port Vizhinjam by defeating the Vel chieftain (the Vel Mannan, who might have been related to the Ay family) and took possession of the Ay-Vel country ("the fertile country along with its magnificent treasures") (Madras Museum Plates of Jatila Parantaka, 17th year).

[8][15] This event is also remembered in the Velvikkudi plates (3rd regnal year, Nedum Chadayan) as "the suppression of the rebellious Ay-Vel" (or at the battle of "nattukkurumbu").

[18] A record of the Kizhan Adikal Ravi Neeli, the wife of Chera Perumal Vijayaraga, can be found in Tirunandikkara, a Shiva temple located in the Ay country.

[18][19] In 898 CE, Vikramaditya Varaguna is seen making huge land gifts to the Srimulavasa Buddhist vihara in the Chera Perumal kingdom (the Paliyam copper plates).

[1][7] The entire region to the south of Trivandrum, including the port of Vizhinjam and Cape Comorin, came under the control of king Rajaraja in the early 11th century.

[1] The kings of Kollam (i. e., Venad), Kodungallur (the Chera Perumal), and Kolladesam (Mushika) were also defeated by the Cholas (Senur inscription, 1005 CE).