John M. Systermans was born Jean-Marie Systermans, but was better known as Father Henry Systermans or Pater Henri Systermans. He was a 20th century Belgian-born missionary and priest with the Congregation of the Sacred Hearts of Jesus and Mary

Congregation of the Sacred Hearts of Jesus and Mary

The Congregation of the Sacred Hearts of Jesus and Mary and of the Perpetual Adoration of the Most Holy Sacrament of the Altar is a Roman Catholic religious order of brothers, priests, and nuns...

.
He served for most of his life in Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 most notably during the 1950s at the leper colony

Leper colony

A leper colony, leprosarium, or lazar house is a place to quarantine leprous people.-History:Leper colonies or houses became widespread in the Middle Ages, particularly in Europe and India, and often run by monastic orders...

 at Kalaupapa

Kalaupapa National Historical Park

Kalaupapa National Historical Park is a United States National Historical Park located in Kalaupapa, Hawaii on the island of Molokai. It was established by the National Park Service in 1980 to expand upon the earlier National Historic Landmark site of the Kalaupapa Leper Settlement...

 on Molokai

Molokai

Molokai or Molokai is an island in the Hawaiian archipelago. It is 38 by 10 miles in size with a land area of , making it the fifth largest of the main Hawaiian Islands and the 27th largest island in the United States. It lies east of Oahu across the 25-mile wide Kaiwi Channel and north of...

. His service there followed in the tradition of fellow Belgian priest, Saint Damien

Father Damien

Father Damien or Saint Damien of Molokai, SS.CC. , born Jozef De Veuster, was a Roman Catholic priest from Belgium and member of the Congregation of the Sacred Hearts of Jesus and Mary, a missionary religious order...

, and his contributions were part of the research gathered by Gavan Daws

Gavan Daws

Gavan Daws writes about Hawaii, the Pacific, and Asia. His best-known works are Shoal of Time: A History of the Hawaiian Islands, in print since 1968; Holy Man: Father Damien of Molokai, the biography of a nineteenth-century missionary priest to Hawaii who served leprosy sufferers, and who has...

 for the definitive biography Holy Man: Father Damien of Molokai.

On August 9, 1958 he was elected as the seventh Superior General of the order.
He served as a Council Father in all four sessions of the Second Vatican Council

Second Vatican Council

The Second Vatican Council addressed relations between the Roman Catholic Church and the modern world. It was the twenty-first Ecumenical Council of the Catholic Church and the second to be held at St. Peter's Basilica in the Vatican. It opened under Pope John XXIII on 11 October 1962 and closed...

 from 1962 to 1965.
On April 17, 1967 Systermans was part of a delegation meeting Pope Paul VI

Pope Paul VI

Paul VI , born Giovanni Battista Enrico Antonio Maria Montini , reigned as Pope of the Catholic Church from 21 June 1963 until his death on 6 August 1978. Succeeding Pope John XXIII, who had convened the Second Vatican Council, he decided to continue it...

 to present petitions advocating beatification

Beatification

Beatification is a recognition accorded by the Catholic Church of a dead person's entrance into Heaven and capacity to intercede on behalf of individuals who pray in his or her name . Beatification is the third of the four steps in the canonization process...

of Father Damien.
He retired in 1970, and died on May 28, 1989.