On August 5, 1930, Astrid of Sweden, Crown Princess of Belgium, was received into the Roman Catholic faith, after two years of religious instruction. Princess Astrid had already been married to Prince Leopold, the heir to the Belgian throne, for nearly four years, and had already born him a daughter, Princess Joséphine-Charlotte. Furthermore, Astrid was eight months pregnant with her eldest son, the future King Baudouin I, who would himself be noted for his devout Catholic faith, most famously, in his conscientious refusal to sign a bill legalizing abortion in Belgium in 1990. Above, we see Queen Astrid, in the company of her husband, King Leopold III, four years after her conversion, kneeling to Cardinal van Roey, Primate of Belgium, at a musical event held on October 9, 1934, at the Cathédrale St. Rombaut, in Malines. The Cardinal authored an account of Astrid's marriage and conversion, entitled, suitably enough, Le mariage et la conversion de la Reine Astrid (1930).
A detailed account of Astrid's marriage and conversion may also be found in the excellent collective work, Astrid 1905-1935, (2005), edited by Christian Koninckx. It is not my intention today to describe all the vicissitudes of the negotiations between the Vatican, the Archbishop of Malines, Cardinal van Roey, the Archbishop of Uppsala, Nathan Söderblom, and the royal courts of Belgium and Sweden prior to the union of Leopold and Astrid, but suffice it to say that it was a highly sensitive, delicate diplomatic matter for all parties. Initially displeased at the prospect of a Catholic prince marrying a Protestant princess, Pope Pius XI eventually granted permission for the wedding to take place, on condition that Leopold and Astrid sign a sworn undertaking to raise their children in the Catholic faith, and that Astrid likewise promise, on oath, not to prevent her husband or children from practicing their religion. As a conciliating gesture towards the Swedes, the Belgian sovereigns had wondered if the Vatican might allow a double religious wedding, a Lutheran ceremony preceded or followed by a Catholic ceremony, but the Catholic authorities refused to permit any such compromise. Only a strictly, emphatically civil marriage in Stockholm, an anomaly in Sweden at the time, was permitted, followed by a religious marriage in Brussels a week later. Furthermore, the religious ceremony was a relatively brief one, since no nuptial Mass took place, in accord with the ecclesiastical regulations regarding mixed marriages.
If Astrid had converted to Catholicism before her marriage, everything would have been much simpler. Yet, the Belgian royal family were concerned that any such conversion should be motivated, not by mere political expediency, but by sincere conviction of the truth of the Catholic faith. The Princess' father-in-law, King Albert I, had confided to Cardinal van Roey that he suspected Astrid would become a Catholic in due course, provided she were treated with gentleness and consideration. Indeed, after her arrival in Belgium, Astrid not only honored the conditions of her marriage, by raising no objections to her daughter's education in the Catholic faith, but also ceased attending Protestant services and began to accompany her husband to Sunday Mass. In 1928, two years after her marriage, she informed Cardinal van Roey, through Leopold, that she desired instruction in the Catholic faith. Canon Dessain, the Cardinal's secretary, became her teacher. Dessain, who had studied law at Oxford, was familiar with Protestantism and spoke fluent English, facilitating his interaction with Astrid, who initially spoke better English than French, let alone Dutch. The Princess' catechesis remained secret, since nobody knew what the outcome would be. By Easter, 1930, however, it was clear that Astrid wished to become a Catholic.
Astrid's formal reception into the Roman Catholic Church took place some months later, on August 5, 1930, in an intimate ceremony in the chapel of the episcopal palace of Malines, in the presence of Prince Leopold, Cardinal van Roey, the Cardinal's secretaries, Canon Dessain and Abbé Leclef, and a Mademoiselle Dessain, who served as the Princess' sponsor. Astrid made her profession of faith and received Confirmation. She had already, of course, been confirmed in the Lutheran church as a young girl, but the Catholic church did not consider the sacrament to be valid. By contrast, no baptism took place, since the Catholic church did view the baptism administered by the Swedish church as valid. The next day, she received the Holy Eucharist for the first time. Astrid's childhood friend Anna Sparre relates in her memoir, Vännen min (1985), that the Princess took her conversion deeply to heart, writing Anna a sober, sincere letter describing the ceremony and declaring that her decision to become a Catholic gave her peace of soul. Apparently, Astrid also touchingly described her conversion, and her first Confession, in a letter to her mother, Princess Ingeborg of Sweden, noting her happiness at finally being able to go to Communion with Leopold. Upon becoming engaged to the handsome Belgian prince, a delighted Astrid had written to her youthful religious educator and mentor, the Archbishop of Uppsala, Nathan Söderblom, that Leopold's soul was even more beautiful than his appearance. Now, it seems, Astrid was pleased to be more fully spiritually united to Leopold, by embracing his religion.