In 1937 the first missionaries of the Order of Franciscan Friars Minor arrived in New Guinea. They started work in the region that fell under the responsibility of the Sacred Heart, MSC ( Missionarii Sacratissimi Cordis, Netherlands). Their centre was in Merauke along the south coast. However, the missionaries also started work in the Bird’s Head Area along the north coast. Before World War II, the missionaries went into areas that had already been visited on previous occasions, such as Steenkool, Sorong. Manokwari and Jayapura, as well as other areas further along the coast.
The North New Guinea Expedition in 1903 was the first official Dutch expedition into New Guinea and its goal was to explore the North Coast of the Dutch part of the island and explore whether exploitable coal beds were present. The exploration concentrated on the Geelvink Bay and Humboldt Bay areas, and also included Lake Sentani. The leader of the expedition was the German Geologist Arthur Wichmann, founder of Earth Sciences at the University of Utrecht.
The Papuan Volunteers Corps was set up in February 1961 to ensure Papuan involvement in protecting the interests of former Dutch new Guinea. It was primarily established for political reasons as part of the Ten Year Plan in 1960 by Cabinet De Quay. Military motives were of secondary interest. The Dutch Government wanted to accelerate the development of the colony in preparation for New Guinea’s independence and as such to keep it from being taken over by the Indonesians. The Papuan Volunteers 
The Korowai people live in the inaccessible jungle in the southeast of the Indonesian province of Papua, about 150 kilometres inland from the Arafura Sea. They are hunter-gatherers in a small society of traditional family ties who need to share all they have in order to survive. Like the Kombai, the Korowai are known for being great architects of tree houses high up in the tree. Until about 1975 the Korowai had hardly any contact with the outside world. 
The local languages in Papua are under threat. This is the disturbing message of the United Nations Organisation UNESCO. The United Nations Cultural Heritage Fund reported that 2498 languages of the World’s existing 6900 languages are in danger of disappearing. This fact is clear from the third edition of the digital ‘Atlas of the World’s Languages in Danger of Disappearing’ presented on 19 February 2009.
A comparison between lifestyle of Papuans living in mountain areas has shown that there are many similarities. One such similarity is that they lived in groups consisting of patrilineal clans. Their leaders were men who needed to prove themselves time and again. Fights and wars between groups of Mountain Papuans were frequent. These usually took place between people who belonged to the same ethnic group.
Differences on the other hand, occurred in performing rituals and establishing trade contacts. 
On 5 April 1961 the New Guinea Council (Nieuw-Guinea Raad) was set up. It was an important moment during a period (1959-1962) in which a more democratic mode of administration started to develop within the Dutch colony. Besides the New Guinea Council, regional councils were also elected, which acted as "subdivisions". These regional councils formed a link between the village councils and the New Guinea Council. 
F.J.P. Sachse on the north coast of New Guinea. Sache is the commander of the Northern Detachment, one of three military exploration detachments that set out to explore New Guinea in the early part of the 20th century. The Northern Detachment consists of Captain Sache and three other officers, 80 Indonesian soldiers, 60 porters as well as labourers, servants, women and children (270 people in total). Five months earlier, they all boarded the carrier ‘Van Den Bosch’. Shortly after landing, they build a base camp along the beach of Humboldt Bay.