 By the early 18th century, the Antemoro had established themselves as major rice and slave exporters.Throughout the 1700s, the Antemoro were embroiled in a conflict with the Ikongo-Tanala that culminated in a bloody Tanala invasion of the eastern coastal plain.Shortly afterward, a major Antemoro leader named Andriamamohotra established an alliance and vassal relationship with the king then ruling Imerina, Andrianampoinimerina, to reestablish peace.