Most of the province consists of the western half of the island of New Guinea, the world's second largest. Beyond it are several islands including two larger ones in the Cenderawasih Bay(2), four significant ones off the northwest, and one big marshy one hugging the southwest corner. The island is wide at the province's border with Papua New Guinea, but the south pulls up quickly as one goes west, and beyond Cape(3) D'Urville so does the north. Past a western neck are two peninsulas: the Boberai and the Doberai or Bird's Head(4). The island's central mountain range, the Maoke, extends from the neck that is south of Cenderawasih Bay, eastward into Papua New Guinea, rising above 5000 meters at Jaya Mountain. Also mountainous are the north of the Doberai Peninsula, the west of the Bomberai Peninsula, and some some of the other islands. But a vast track of southwest New Guinea, as well as the south of the Doberai Peninsula are flat and marshy. Many rivers flow through the swamps, the Digui and the Pulau among them. North of the Maoke, the Mamberamo River flows to Cape D'Urville. Its two feeds define a valley between the Maoke proper and the lower Van Rees range paralleling them to their north. A third range begins behind the capital--in the northeast--and extends discontinuously into the neighboring nation.
Just over two and a half million people live here. There is no majority first language; perhaps many learn Indonesian(5) as a second language. Recent migrants from Java(6) and their descendents speak Javanese but it is difficult to know how many they are. I've guessed less than one in ten. About the same number speak Ekari and closer to one in five speak Western Dani. Dani and Ekari are both Trans New Guinea languages, more exactly part of that group's Central and Western Main Section. This subgroup accounts for more than six in ten speakers; the group in its entirety for more than seven in ten. West Papuan languages account for more than one in twenty, and Malayo-Polynesian languages--including Javanese--for less than one in five. A total of six other groups and at least one unclassified language account for the rest--about one in twenty.
Christians are an overwhelming majority--said to be 85% in 1991, divided about three to one, Protestants over Catholics. Moslems are said to be 15% in 1991--most of these are the Javanese.
The capital, Jaya Pura(7), is the province's largest city--though not by much; it has less than 200 thousand residents. Its claim to fame is having been the headquarters for the American general, MacArthur, during World War II.
Humans got there tens of thousands of years ago--25 to 40 thousand according to different estimates. Some speculate that the non-Malayo-Polynesians--the several local unrelated linguistic groups--have been around for most of this time. Only two groups have linguistic connections beyond the island. One of them is the West Papuan group, but it isn't clear if these languages co-evolved or if there was a migration, nor--if there was a migration--whether it went west to Halmahera or east to Papua. The other is a branch of the Trans New Guinea group that has relatives on Timor. The spice-based sultanate of Ternate, near Halmahera, introduced Islam to the Doberai (Bird's Head) Peninsula. It didn't spread beyond a few Papuan communities until the Javanese arrived.
The Malayo-Polynesians came later, but still long ago. The Central group went south from the Philippines towards the Moluccas and Lesser Sundas; it was barely represented in Papua before the Javanese arrived. The Eastern group also came from the Philippines, one group arriving in Halmahera and western Papua, and the other pushing across the big island's north coast (and beyond).
The last of the Malayo-Polynesians were the Javanese, part of the Central group, arriving after Indonesia conquered Papua in the second half of the 20th century. With these migrations the number of Moslems rose.
Christianity came by missionaries during the time the Dutch rule the west of the island--roughly for a century, partly in the 19th and partly in the 20th.
north
east
south
west of the Bomerai Peninsula and south of Misool Island
west of the Doberai (Bird's Head) Peninsula and nearby islands
(1) Formerly it was Irian Jaya (that is, 'victorious, arising out of the sea'); before that it was Dutch New Guinea.
(2) The Indonesian word for 'bay' is 'teluk'.
(3) The Indonesian word for 'cape' is 'tanjung'.
(4) Two Indonesian words are used for 'peninsula': 'jazira' (which resembles the pan-Moslem word for 'island') and 'semenanjung'. The Dutch word for the 'Bird's Head' peninsula is Vogelkop.
(5) Called Malay or Malaysian outside of Indonesia.
(6) More properly spelled Jawa.
(7) Formerly Hollandia among other names.