Battle of Formoso River

Battle of Formoso River
Part of Acehnese–Portuguese conflicts
Date 27 November – 2 December 1615[1] Location Formoso River[1] Result Portuguese victory[1][2]
Belligerents
Portuguese Empire	Aceh Sultanate
Commanders and leaders
Francisco de Miranda Henriques Diogo de Mendonça Furtado	Iskandar Muda
Strength
4 galleons[1] 6 half-galleys 10 jáleas[1]	300[3] – 500 vessels[4][2] 100 galleys[1] 150 ghurabs.[1] 250 junks, lancharas, calaluzes.[1] 30,000,[3] 40,000[1] or 60,000 men[2][4]
Casualties and losses
1 galleon, 1 half-galley, 100 dead, 30 POWs.[1]	20,000 men, 200 POWs.[1]

The Battle of Formoso River of 1615 was a naval battle that took place in the Malay Peninsula in the Formoso River, between a Portuguese fleet and a large fleet of the Sultanate of Aceh, one of the largest Aceh had ever mobilized against the Portuguese in Malacca.^[1][5]

In what was "one of the bloodiest battles the Portuguese fought in south-east Asia", the Acehnese suffered so much damage they were forced to call off their plans to attack Malacca and returned to Aceh.^[1]