Ammachi Panapillai Amma

The Maharajahs of Travancore (current south Kerala) adopted the Matrilineal custom and inheritance prevalent in the land around the 14th Century AD.

It is believed that when the then Travancore King, Maharajah Sree Karthika Thirunal Dharamaraja shifted capital from Padmanabhapuram to Thiruvananthapuram, he brought along his four wives who belonged to the places namely Vadasseri, Nagercoil, Arumana, and Thiruvattar.

[1] The Kings of Travancore traditionally took wives from Ammaveedus and the Consorts, known as Ammachis would get the additional title of Panapillai Amma.

But, unlike other Sudra unions, the Ammachi, having once been married to a Rajah, is required to remain single all the remainder of her days; and is shut up and guarded in her own residence.

Precisely similar is the custom in China, where, on the death of an emperor, his women are removed to a portion of the palace, in which they are shut up for the remainder of their lives.

....[3] Despite all these limitations, historians point out that the Ammachis were compensated with material benefits like tax exemption to land and other properties, comfortable living provisions as well as other honours.