[5][6][7] Initially, their influence appeared to be limited to the area between present-day Quilon and Quilandy, but it later extended up to the Chandragiri river in northern Kerala and to Nagercoil in the south.

[12] Nambudiri-Brahmin settlements of agriculturally rich areas (fertile wet land) were another major source of support for the Chera state.

[2][14][15] However, modern scholars have criticized these early Kerala historians for inventing a "Second Chera Empire " to rival the glories of the imperial Cholas (in the Tamil country).

[16] However, critical research in the late 1960s and early 1970s offered a major corrective to this view (by suggesting 'a monarchy supported by a Brahmin oligarchy').

[6] His kingship was only ritual and remained nominal compared with the power that local chieftains (the udaiyavar) exercised politically and militarily (in distant north and south Kerala).

[20] The Chera/Perumal dynasty introduced "kingship" as a form of rule in Kerala, marking a departure from the early historic system of clan-based societies.

[4] It is speculated that Kerala's rulers faced little economic pressure for territorial conquest, as the region was naturally rich and derived (a substantial) income from the trade with the Middle East.

[11] The kingdom was attacked and eventually forced into submission by the Cholas in the early 11th century CE (to break its near monopoly on trade with the Middle East).

These were the transit areas, ports of call for the Arab traders and ships to Southeast Asia and China, which were the source of the valuable spices sold at a high profit to Europe.

"The Perumal kingship remained nominal compared with the power that local chieftains, the so-called "nattu-udaiyavar" or "nadu-vazhumavar", exercised politically and militarily.

[15] The Chera Perumal only held direct authority over the country that extended from Palakkad to Vembanad Lake, including the port of Kodungallur.

[2][15] Prakrithi was a body of non-Brahmin or Vellala notables that assisted the udaiyavar, while the Adhikarar were temple or royal servants responsible for management, the collection of dues, or serving as local arbitrators.

From north to south, they are as follows: Kolla-desam (or) Kolathu-nadu (proposed name[28]), Purakizha-nadu, Kurumporai-nadu, Erala-nadu, Valluva-nadu,[15] Kizhmalai-nadu (the Eastern Hill Country[29]), Vempala-nadu, Munji-nadu, Nanruzhai-nadu[15] and Venadu or Kupaka (Kollam[28]).

[15][30] The Perumal held direct (sovereign) authority over the country that extended from Palakkad to Vembanad Lake (including Kodungallur in the Periyar Valley).