Wikipedia
Yakadadolis were aristocratic concubines in the Harems of mainly the Kandyan Kings of Sri Lanka.
Ladies of Radala and other higher castes were taken into the Harem as Yakadadolis, not as and Randolis (princesses). Favourite concubines frequently received land grants and their offspring were appointed as high officials of the royal court, and in a few cases captured kingdoms by deposing less scandalous and more legitimate heirs to the throne.
The daughter of the Bintenne Disawa and granddaughter of Mámpitiye Dissawa was a Yakadadoli in the Harem of the Nayakkar King Kirti Sri Rajasinghe (AD 1747 - 1782), and had a very capable and popular son by the King, named Mámpitiya Bandára. However Mámpitiya Bandara was not considered as an heir to the throne on account of the king's brother's presence at court . Following South Indian succession traditions, Kirti Sri Rajasinghe overlooked this illegitimate son, and selected his brother, a Náyakkar prince, as the heir to the throne. The Yakadadoli however was againselected as a mistress of Kirti Sri Rajasinghe's successor Rajádhi Rajasinghe (A. D. 1782 - 1798).
As part of customary law, if someone sought refuge in the house of a Yakadadoli they could not be arrested.