Johannes Cornelis Princen (21 November 1925 – 2 February 2002), also known as Poncke Princen, was a Dutch anti-Nazi fighter and activist. In 1948, he deserted the Dutch military, and joined the Indonesian independence guerrillas in the Dutch Indies.

For his anti-Nazi activities, he was imprisoned in several Nazi prisons and camps in the Netherlands and Germany. After defecting to the Indonesian guerrillas who opposed Dutch rule, he lived the rest of his life in Indonesia, where he became a human rights activist and political dissident. Owing to his activism, he spent time in detention in Indonesia.

Early life Princen was born in The Hague, Netherlands to socialist parents. His great-grandfather had been a deserter from military service and had long been chased by the authorities.

Despite his upbringing, Princen took interest in Catholicism, influenced by his grandmother, Theresia Princen-Van der Lee. In 1939, he entered the Holy Ghost Seminary at Weert – where he was followed by his younger brother Kees Princen, with whom he was to maintain correspondence throughout his life. In 1940, while he was at the seminary, Nazi Germany invaded and occupied the Netherlands.

In 1942, at age 17, he was accepted as an economic counselor at Teppemaand Vargroup Groothandel voor Chemische Producten, a chemical company in The Hague. Eventually, he quit the job to take up arms against the Nazi occupation of the Netherlands.

Nazi imprisonment and liberation In 1943, Princen was arrested by the German occupation authorities in Maastricht while trying to travel to Spain. He intended to travel to Britain from Spain and enlist in an Allied army fighting the Nazis. He was convicted by the occupation authorities of "attempting to aid the enemy" and in early 1944 was sent to the notorious Vught Camp.

On June 6, 1944, he was transferred to the Kriegswehrmachtgefängnis (Wehrmacht military prison) at Utrecht. While there, he entertained fellow prisoners by reading from a favorite book, Pastoor Poncke ("Pastor Poncke") by Jan Eekhout. This led to his nickname of "Poncke", which he was to keep for the rest of his life.

He was transferred to the prison camp at Amersfoort and from there to Beckum, Germany. Before being liberated by the arrival of Allied forces, he passed through seven Nazi prisons and camps.

After being freed from Nazi imprisonment, Princen joined the Stoottroepen Regiment Brabant (Brabant Stormtroop Regiment), based in the southern Dutch province of North Brabant.

In 1945, he worked for the newly founded Bureau voor Nationale Veiligheid (Bureau of National Security :nl:Bureau Nationale Veiligheid), forerunner of the Dutch Security Service – mainly involved in hunting down collaborators and war criminals, but also surveilling natives of the Dutch Indies who lived in the Netherlands, who were sympathetic with the rebellion against Dutch rule that was spreading in their homeland.

Colonial service In March 1946, Princen was called up to join the ranks of the Royal Netherlands Army and take part in what Dutch histories still call 'Police Actions' () but which became better known as the Indonesian National Revolution.

Reluctant to take part in the war, Princen fled to France – but upon hearing that his mother was ill, came back and was arrested by the Marechaussee and detained at Schoonhoven. On December 28, 1946, he was put on board the troop ship Sloterdijk. Also aboard the Sloterdijk was the Communist Piet van Staveren, likewise a reluctant conscript who would eventually desert and join the Indonesian rebels. Both of them did meet during the trip and sharing their anti-colonial ideas.

When he arrived in the Indies, Princen was charged with desertion. On 22 October 1947, he was sentenced to twelve months' imprisonment for desertion, but he was returned to active service after four months at the Tjisaroea Prison Camp, the remainder of his sentence being suspended. He was increasingly unhappy with the haughty and contemptuous attitude of fellow soldiers to the local population, and he was present at some violent incidents which greatly increased his disaffection. As he many years later explained, "An adolescence under Nazi rule and two years in German imprisonment has directed my life and made me fight against cruelty. I thought the Indonesians were right. I thought they should be the ones to decide their own future. (...) I was disgusted with the Dutch killing people I admired".

In January 1948, the United Nations brokered a fragile cease-fire, but almost immediately both sides violated the truce in multiple incidents and the Dutch forces made preparations for a new operation against the rebel forces. It was at this time, while being on leave at Sukabumi, that Princen crossed the Line of Demarcation into rebel-held territory, and via Semarang reached Yogyakarta, the provisional capital of the self-proclaimed Indonesian Republic – where the suspicious Indonesian nationalists threw him into prison.

As an Indonesian guerrilla In December 1948, the Dutch army launched Operation Kraai (Dutch for "Crow"), captured Yogyakarta, and imprisoned Sukarno and other most nationalist leaders. During the assault upon the provisional capital, the nationalist rebels released Princen from their prison and gave him the chance to enlist in the Tentara Nasional Indonesia (TNI, Indonesian Republican Forces). When he joined them, the pro-independence forces' fortunes seemed at their nadir, with their political leadership captured and most of the territory of Indonesia under a re-established Dutch military rule. They conducted an intensive guerrilla campaign and gained considerable international sympathy and support.

Princen was fully committed to his new cause, seeing front-line service under Kemal Idris and taking part in the fighting retreat of the Siliwangi Division under then-Colonel A. H. Nasution, from Central Java to "guerrilla cantons" established in West Java – an action which came to be known as the Long March Siliwangi (derived from the famed Long March of Mao Zedong's Chinese Communist Party). He was appointed staff officer in the Second Brigade of Grup Purwakarta, active in the environs of the city of Purwakarta.

On one occasion in the beginning of August 1949, Dutch troops shot Princen's wife Odah, with Princen narrowly avoiding being killed. When asked in a press interview many years later "Did you actually shoot at Dutch soldiers? Did you kill some of them?" he answered forthrightly "Yes, I did."

Princen became famous (or notorious, according to point of view). In a struggle decided as much in the international public opinion and diplomatic forums as in the field, the presence of an articulate ex-Dutch soldier with an anti-Nazi past in the rebel ranks had a political and propaganda significance. Princen's act aroused bitter hostility against him from the Netherlands. Some accused him of having allowed himself to be used as bait to draw Dutch soldiers into an ambush which led to a high number of KNIL (Koninklijk Nederlands Indisch Leger - Royal Netherlands East Indies Army) fatalities. A Dutch court martial sentenced him to death in absentia, and when the Dutch finally decided to evacuate Indonesia, they made a demand for his extradition. Sukarno, the first president of Indonesia, did not agree. Instead, on October 5, 1949, he awarded Princen the , the highest decoration of Indonesia.

Princen's career as a rebel and dissident continued. He was imprisoned repeatedly, both by Sukarno and by Sukarno's rival and successor Suharto, spending a total of eight and a half years in prison. The decoration he received from Sukarno – a small five-pointed bronze star on which were etched the words "Pahlawan Gerilja" (Guerrilla Hero), and which Princen conspicuously displayed until the end of his days – was to give him at least some protection from the most harsh forms of repression to which successive Indonesian regimes resorted against many other dissidents and political opponents.

As dissident parliamentarian, political prisoner After the war Princen married again – this time to a Dutch woman named Janneke Marckmann (until 1971) and later to Sri Mulyati, who was to remain his companion until his death. He had four children: Ratnawati, Iwan Hamid, Nicolaas and Wilanda.

His desire to "immerse himself in Indonesia" was manifested in a conversion to Islam, the predominant religion in Indonesia. Asked why he had changed his religion, he later explained to a visitor: "I wanted to feel a part of what everyone else was doing". In later life, his name was on some formal occasions preceded by the Muslim honorific Hajji, usually bestowed upon those who had gone on pilgrimage to Mecca.

Between 1950 and 1953 Princen was an official at the Indonesian Immigration Office. In 1956 he became a Member of the Indonesian Parliament on behalf of the (IPKI), and was considered a representative of the foreign minority in Indonesia. As a parliamentarian he repeatedly posed questions to the Sukarno Government, on such issues as the unequal division of national resources and income between the central island of Java and the outlying islands. He was apparently one of the "obstructing parliamentarians" whom Sukarno found annoying and whose activity was among the factors which led the President to replace the Western-type parliamentary system with "guided democracy" in 1959.

Princen's outspoken criticism caused him to be arrested and imprisoned in 1957–58. He spent Sukarno's final years, characterized by increasingly violent power struggles in Indonesia, again serving a prison term 1962–66.

Human rights activism Having come to strongly oppose Sukarno, Princen initially placed some hopes in Suharto, who overthrew him in the Transition to the New Order following the 1965 attempted coup d'état of the 30 September Movement and whose coming to power had the incidental effect of getting Princen released from prison after four years. The Suharto regime proved both extremely brutal and highly corrupt: "My opinion of Mr. Suharto changed at the moment he started gathering as much money as he could for himself."

In the late 1960s, Princen was a correspondent for Netherlands Radio and several Dutch newspapers. This was directly connected with his work as a human rights activist, in which he was to spend most of his time and energy for the remainder of his life. In 1966 Princen founded and headed Lembaga Pembela Hak-Hak Azasi Manusia (Indonesian Institute for the Defense of Human Rights). It was the first human rights organization in Indonesia, and which handled many high-profile cases during the years of the Suharto dictatorship and provide a reliable alternate source of news to Western journalists in Jakarta. Among the earlier campaigns which Princen conducted was on behalf of the left-wing writer Pramoedya Ananta Toer, imprisoned and tortured by the Suharto regime. At the end of 1969 he published, jointly with the journalist Jopie Lasut, an extensive report on the mass murder of Communist sympathizers at Purwodadi in Middle Java – for which Princen and Lasut were arrested and interrogated.

This was followed in the early 1970s by Princen's prominent role in creating a larger organization, the Indonesian Legal Aid Institute (LBHI), where he met with many other human rights figures including Adnan Buyung Nasution, Frans Winarta, Besar Mertokusumo, Yap Thiam Hien, Victor D. Sibarani, Mochtar Lubis, Albert Hasibuan and members of the younger generation of activists.

The eulogy published after his death by the Indonesian oppositional news and commentary website Laksamana. Net noted that

Prisoner again, labor advocate, political reformer