Who was the ruling power of southern provinces in Mekong delta?

The ruling power of the southern provinces in the Mekong Delta was predominantly the Nguyen dynasty of Vietnam during the 19th century. The region was integrated into Vietnam's territory through a series of military campaigns and administrative reforms. Prior to that, various local kingdoms and groups, including the Khmer Empire and the Cham, exerted influence over the area. The Nguyen dynasty's control helped to establish Vietnamese cultural and political dominance in the Mekong Delta.