The chapel was rebuilt in a a glade near the grassy esplanade to the south of the mansion of Argenteuil. In this intimate, mystical little sanctuary, Leopold and Lilian would practice their religion for decades. Princess Lilian, in particular, almost never attended any other place of worship. For forty years, her spiritual needs were served at Argenteuil by her confessors, including Henri Collart, S. J. and Raymond Thils, a brave military chaplain, greatly admired by the King and his wife, who had served in the Resistance during World War II.
Unfortunately, the Belgian government did not allow Lilian to be buried at Argenteuil as she had hoped. Prior to her funeral at Laeken, however, her children, Alexandre and Esmeralda, organized a memorial service in her beloved chapel to honor at least the spirit of her last wishes. Monsignor Édouard Massaux, rector of the Catholic University of Louvain, and a friend of the Princess, delivered a moving homily, pondering the mystery of human death and the hope of the Resurrection. He also described the viciously vilified Lilian of Belgium in noble, touching terms:
"It is a great Lady who has just left us... All those who truly knew her well and who often spent time with her knew what she was, knew her brilliant intelligence, her opinions, her passions, her vast culture, her indefectible attachments, her courage in the many ordeals she endured, her great tolerance, her respect for the convictions of others, her unfailing fidelity to the causes dear to her. They knew her acceptance of living in the shadows for many years without the slightest resentment...her very great generosity towards the poor and the most disadvantaged, whom she aided financially, with attentiveness and in total discretion, even traveling abroad if it were necessary to do so."Christian de Duve, Nobel prize winner and close collaborator of the deceased princess in her Cardiological Foundation, later remembered the precious moments he had spent in the humble but delightful medieval chapel:
"[A]llow me to recall with special emotion those intimate gatherings in the lovely Argenteuil chapel, where, each year, on the 25th of September, the military chaplain Canon Thils with the faithful Guy in attendance, celebrated the souvenir of the late King, and where, on June 10 of last year, we said our last goodbye to our beloved Princess."(Christian de Duve, "Princess Lilian: reminiscences", in Proceedings of the Princess Lilian Cardiology Foundation Symposium to commemorate its Patron, HRH Princess Lilian of Belgium, "Cardiology and cardiovascular surgery at the onset of the XXIst century," Acta Cardiologica- An International Journal of Cardiology, suppl. to volume 59, 2004, p. 16, quoted by Michel Verwilghen in Le mythe d'Argenteuil, 2006, p. 62)