What is "ratsimilaho"

Ratsimilaho (c.1694 – 1750) was a ruler of an east coastal region of Madagascar. He is said to be the son of an English pirate (possibly Thomas Tew) and a Malagasy queen regnant, Antavaratra Rahena. The region, known as the Betsimisaraka confederation covered of coast and this legacy was created by Ratsimilaho. The Betsimisaraka make up approximately fifteen percent of the Malagasy people and are the second largest group in Madagascar after the Merina.