Although the existence of the islands and their inhabitants was long known to maritime powers and traders of the South– and Southeast–Asia regioncontact with these peoples was highly sporadic and very often hostile; as a result, almost nothing is recorded of them or their languages until the mid-18th century. From the 1860s onwards, the setting up of a permanent British penal colony and the subsequent arrival of immigrant settlers and indentured labourers mainly from the Indian subcontinent brought the first sustained impacts upon these societies, particularly among the Great Andamanese groups.