appointed Hengen the titular bishop of Calama and coadjutor bishop on 8 April 1967, with right of succession. On 4 June 1967 he was consecrated in Notre-Dame Cathedral. On 12 February 1971, after Léon Lommel retirement, Hengen became the sixth Bishop of Luxembourg. His motto as Bishop was "Tibi servire". On 13 May 1972 he convened the 4th Luxembourgish diocesan synod, which was to be a synod of renewal. When the old bell-tower of the Cathedral was in flames on Good Friday in 1985, he personally saved the statue of the Virgin Mary – an important Luxembourgish symbol – and later took care of planning the reconstruction. The same year, Pope John Paul II personally appointed him the first Archbishop of Luxembourg on 16 May during a visit to the country. In 1988 Luxembourg was elevated to an Archdiocese. Jean Hengen was also the president of the German commission responsible for publishing liturgical books. One big project of Bishop Hengen was a church at the service of young people. Under him, the Pélé des Jeunes started in 1974, which to this day takes place on the first Sunday of the Octave celebrations. Other high points of youth ministry were the meeting of young people with John Paul II in Echternach during the papal visit of 1985, and Youth Day, a national version of the World Youth Days.
Retirement
With the consecration of Fernand Franck as his successor on 2 February 1991, Jean Hengen's tenure as Archbishop came to an end. In this time in office, he had always tried to avoid favouring his home town of Dudelange over other Luxembourgish cities. Thus, while he declined Abbot Robert Sibenaler's invitation to the Octave Mass of the Dudelange pilgrims during his time as Bishop, after his retirement he willingly participated in this tradition. After his death, flowers were laid in the crypt for the people of Dudelange every year after the Octave Mass. On 29 October 2000 he celebrated his diamond jubilee as a clergyman. Dudelange also honoured "its" Bishop on 23 November 2002 for his 90th birthday, which was also the last Mass that he would celebrate as Bishop. His last public appearance was on 10 May 2004at the Octave Mass with the Dudelange pilgrims. On this occasion, he did not wear a Bishop's ornaments such as a staff and mitre, but a simple violet Bishop's cassock and a rochet. Jean Hengen died in the hospital on Kirchberg at 12:00 on 29 January 2005. His remains were buried on 2 February 2005 in the crypt of Notre-Dame Cathedral in Luxembourg.