In April 1957, he married Nicoleta Valeria Bruteanu (1919–96), a graduate of Bucharest Conservatory, relative of Iuliu Maniu and former political detainee. The Romanian movie Binecuvântată fii, închisoare (Bless you, prison) and the book Prisoner Rejoice[4] recount the story of Nicoleta Valeria Bruteanu's grueling years of detention by the Romanian Communist Regime. On 7 March 1959 Grossu was arrested and sentenced to 12 years in prison for his activity in Oastea Domnului.[5] He was pardoned in 1962.[6] The communist dictatorship then denied him all but manual employment.[7]
Sergiu Grossu and his wife migrated to France in 1969. There they founded the "Catacombes" publishing house, the association "La Chaine" and served as editors of the monthly magazine Catacombes (1971–92). He hosted the radio show "Lumea creștină" on Radio Free Europe, and lectured in Paris, Bordeaux, Versailles, Besançon, Dieppe, Tours, Blois, Poitiers, Nantes, Brest, Toulouse, Lyon &c.
On 18 January 1996, after 27 years in exile, Sergiu Grossu returned for good to Bucharest, bringing with him the mortal remains of his wife. In Bucharest, he founded Fundația Foștilor Deținuți Politici "Nicoleta Valeria Grossu", the publishing house "Duh și Adevăr", and the association "Centrul de cultură creștină Nicoleta Valeria Grossu."
In Chișinău Sergiu Grossu founded Centrul internațional de cultură pentru copii și tineret "Sergiu Grossu" and sponsored the creation of the Muzeul Memoriei Neamului, led by his former classmate Vadim Pirogan.[8]
Honours
Premiul concursului de creație literar-creștin "Sergiu Grossu"
Centrul internațional de cultură pentru copii și tineret "Sergiu Grossu"
ziarul "Catacombes"- 1971, editat timp de 20 de ani
Catacombes 1973 (Almanach de l'Église de Silence), 1973, Éditions Catacombes
Câmpurile de muncă în URSS, 1975
Derrière le rideau de bambou (de Mao Tsé-toung à Fidel Castro), 1975, Éditions Catacombes, Paris
La Technique du regard în Promesses - Revue de réflexions bibliques, N°15, Jul–Sep 1975
The Church in today's catacombs, Arlington House, USA, 1976
Grassu, Sergiu (1996) [1976, Éditions Catacombes], Vania Moisséieff, Le jeune martyr de Volontirovka, Paris: Apostolat des Editions.
Infernul chinez, 1976
Au fond de l'abîme (Le règne de la haine), 1976, Éditions Apostolat des Éditions, Paris
Les Enfants du Goulag (Chronique de l'enfance opprimé en URSS), 1979, France-Empire, Paris.
——— (1987), Le calvaire de Roumanie Chrétienne, France-Empire
——— (1998) [1988], Maîtresse, Dieu existe! Les enfants dans l'étau de l'athéisme soviétique [Teacher, God exists! Children in Sovietic Atheism] (in French), Paris: Fayard.
——— (2006) [1992, Convorbiri literare - ABC DAVA], Calvarul României creștine (in Romanian), Vremea.
Inscripții pe un vas de lut – 1994, ed. Roza vânturilor
În șfichiul ironiei – 1996, ed. Hrisova, Bucuresti
În așteptarea unui pământ nou – 1998, ed. Duh și Adevăr
Îmi bate inima la Bug, ed. Museum, Chișinău, 2000
Apocalipsiada
——— (2002), Berthoud, Jean-Marc (ed.), L'Église persécutée, entre goulag & société opulente ; chronique de deux Roumains à Paris, "Catacombes", septembre 1971-décembre 1992 [The persecuted Church, between the gulag and the oppulent society: chronicle of two Rumanians in Paris, "Catacombs", Septembre 1971 – December 1992] (paperback), Messages, Lausanne: L'Age d'homme, ISBN978-2-82511735-4.
Plaidoyer pour L'Église du Silence, Ed. Resiac, 2003
Calendarul persecuției religioase în țările comuniste, 2003
^Grossu 2002, pp. 12–20: 'Je ne veux pas insister sur la période sinistre de mon emprisonnement, ni sur les temps difficiles que j'ai connus après ma libération : obligé d'accomplir un travail manuel dans un chantier de construction, en ma nouvelle qualité « d'ancien détenu politique ». [I do not want to insist on the dark period of my detention, nor on the hard times I knew after my liberation: forced to perform manual labour in a building site, in my new quality of "old political prisoner".]'