Because of the Nazi invasion of the Netherlands during World War II the Dutch Royal family was forced to live in exile in Canada where Irene attended public school. As a teenager, she was dubbed by the Dutch press as "the glamorous Princess of the Netherlands."
Princess Irene studied at the University of Utrecht then went to Madrid to learn the Spanish language. There, she met Prince Carlos Hugo de Bourbon-Parma, Duke of Parma, a Carlist pretender to the throne of Spain and a leader in General Francisco Franco's fascist Falange party. In the summer of 1963, Princess Irene secretly converted from Protestantism to Roman Catholicism. The first the public or the Royal Family knew about the conversion was when a photograph appeared on the front page of an Amsterdam newspaper showing the Princess kneeling at a Mass in the Royal Catholic Church of los Jerónimos in Madrid. News leaked out that she was engaged to Prince Carlos Hugo (b.1930), provoking a Protestant outcry and a constitutional crisis.
Although it was a constitutional tradition and not a law that forbade a Catholic to reign over the Netherlands, it was a practice predicated upon a history of the Protestant-dominated Dutch Senate (States-General) born out of the 16th-century war with Spain. Fears of Catholic domination had increased over the centuries through difficulties and wars over the policies of many neighboring Catholic European countries and the precedent created by the ascension of a member of the House of Orange to the throne of England solely because he was Protestant. By the middle of the 20th century religious attitudes had begun to change, but only very slowly. While members of the Roman Catholic Church accounted for approximately 34% of the Dutch population, the Roman Catholic People’s Party of the Netherlands came to power in 1959 and held a plurality of members in the lower house when the crisis over Princess Irene’s conversion and marriage took place.
Amplifying the crisis over a Royal conversion to Catholicism and a marriage without approval of the Dutch States-General (which the Princess, then second-in-line to the throne, knew she would never get), were the still very fresh memories of the fascist General Franco's support for Nazi Germany. For the second in line to the throne not merely to convert to Roman Catholicism but associate with a leader of Franco's party, caused shock and consternation in the Netherlands.
Queen Juliana attempted to stop the marriage, first by sending a member of her staff to Madrid to persuade the Princess not to go ahead with a marriage that was a political disaster for the monarchy in the Netherlands. It seemed to work and the Queen went on Dutch radio to tell the citizens that Princess Irene had agreed to cancel her engagement and was returning to the Netherlands. However, when the airplane arrived at Schiphol Airport, the Princess was not on it, and Queen Juliana and her husband, Prince Bernhard were supplied with a Dutch military plane to go to Spain to retrieve their daughter. However, a message was delivered to the Queen from the Dutch government warning that it would resign en masse if she set foot in Spain. Given the ramifications and the fact that no monarch from the House of Orange had ever visited Spain, the Queen had no choice but to turn back.
It was suggested that Princess Irene was a pawn of General Francisco Franco who tried to maximize the event to his benefit. In early 1964 Princess Irene flew home in the company of Carlos Hugo where an immediate meeting took place with the couple, the Queen, Prime Minister Marijnen, and three top cabinet ministers. In an attempt to gain public favour for her proposed marriage, Princess Irene publicly stated that her marriage was intended to help end religious intolerance. This caused a division in public opinion, as less than 40% of the country ruled by the Protestant House of Orange was Roman Catholic. Over the ensuing weeks, things deteriorated further when Pope Paul VI granted an Audience requested by the couple in Rome. The Queen at first denied such a meeting had taken place, but it was later verified. Irene alienated herself from most every Dutch citizen when a photo appeared in a Dutch paper showing Irene at a Falange rally in Spain and she declared that she supported her fiancé's Falangist politics.
No one from the Dutch Royal family or any Dutch diplomatic representative attended the marriage of Princess Irene and Prince Carlos Hugo in the Santa Maria Maggiore Basilica in Rome, Italy on April 29, 1964. Because she had failed to obtain the approval of the States-General to marry, Irene lost her right of succession to the Dutch throne. She agreed that she would live outside of the Netherlands.
After the marriage, Irene was very active in her husband's right-wing political cause, but over time they drifted away from extremism and became a part of the international jet-set crowd. The prince, head of the Royal House of Bourbon-Parma, became a naturalized Spanish citizen in 1979. The couple had four children, but the marriage ended in divorce in 1981. Irene returned to live in the Netherlands with her children and would become involved in various personal development workshops, trying to "find herself." Her connection with nature, that she says she had felt since childhood, intensified and in 1995 she published her book Dialogue with Nature. The book outlined her philosophy that human beings are alienated from the natural world, but the Dutch media seized upon passages that recounted conversations she said she had with the trees and dolphins.
The children of Princess Irene and Prince Carlos Hugo de Bourbon-Parma are: