The Dayaks are descended from a common Austronesian migration from Asia some 3000 years ago.
This is the view hold by most modern anthropologists on the indigenous peoples of South East Asia,
The early populations spoke several languages and dialects falling under the term Austronesian Lingua. Dayak languages can be traced to that common language. About 2500 years ago, metallurgy was introduced and subsequently became used by most of the populace. There are numerous ethnic groups within the Dayak population.
The Dayak people of Borneo have an indigenous account of their history, partly in writing and partially as a part of their common cultural practices. They cultivated political relationships during the colonial times with outside peoples and there is a large body of information regarding their migratory behavior.
Coastal populations in Borneo are largely Muslim in belief; however, these groups are generally considered to be Islamized Dayaks, native to Borneo.