Where do most of the old immigrants born and raised in East Timor come from?

Portugal. The Democratic Republic of East Timor, referred to as East Timor for short, is an island country located at the eastern tip of Nusa Tenggara Islands. East Timor was once a colony of Portugal, and later became independent. Timor-Leste also includes Oecussi area in the east and west of the northern coast of Timor Island, and atauro island and Yaku Island near the eastern end.