According to a Marconi Wireless telegraph message to the New York Times dated February 2, 1908, Marie Juliette Louvet was the the morganatic spouse of Prince Louis II of Monaco. This means that his marriage to Marie was never recognized as dynastic by Prince Albert I. This morganatic status is the root of the claims that their daughter, Charlotte, was illegitimate. Truth is she was likely legitimate, but had to be formally adopted by Louis in order to acquire dynastic succession rights. If Louis never married Marie Louvet, why did he not marry another woman to father a much needed male heir? Answer is that he was already married to Marie. He claimed that this marriage was religious. We will never know. Marie was previously married and divorced with two children- this maybe why her marriage to Louis could never be dynastic. Louis only married his second wife, Ghiselline, sometime after the death of Marie Louvet. All the surviving evidence points to a marriage between Louis and Marie which was not recognized as dynastic by his father Prince Albert I, but may have been fully legal, and also religious.
I have miraculously discovered an article brilliantly authored by Frederick Cunliffe-Owen, in the archives of The New York Times, dated July 9, 1922. This article reveals the marriage between Prince Louis II of Monaco and Marie Juliette Louvet. According to Cunliffe-Owen, Louis married his mistress, Marie Louvet, without his father's consent. This marriage was both civil AND religious. When Prince Albert found out about it he declared the marriage morganatic, and insisted that Louis have the marriage anulled. However Louis refused, and furthermore, Louis insisted that the marriage was dynastic, not morganatic- Louis was fully supported by the Papacy and the Church of Rome. Eventually, a reconciliation was achieved between father and son. When Prince Albert was introduced to his baby grand-daughter, he fell in love with her. However, instead of formally recognizing her as his legitimate grand-daughter, he formally adopted Charlotte as his own daughter, making her heiress of Monaco after Louis. This act seems to indicate that Albert never recognized the dynastic status of the legal marriage. She was later married to Pierre de Polignac- representing the junior line of the Polignac noble family.
In the eyes of the Catholic Church, Charlotte was both legitimate and dynastic. Cunliffe-Owen further claims that the German Kaiser, Wilhelm II tried to use Louis' controversial marriage to get Albert to set aside his son's succession, and apoint his nephew, the German Duke of Urach as his heir, but Albert refused. Prince Albert, originally a good friend of the Kaiser, later turned against him. See article entitled "Prince Louis's Notable Career" in the archives of The New York Times. Cunliffe-Owen claims that Louis and his father were on excellent terms at the time of Prince Albert's death in 1922. Louis was a highly respected French General at the time of his accession.