On 11 January 1999, Queen Elizabeth II issued a Declaration in Council, "My Lords, I do hereby declare My Consent to a Contract of Matrimony between His Royal Highness Prince Ernst August Albert of Hanover, Duke of Brunswick-Luneburg and Her Serene Highness Princess Caroline Louise Marguerite of Monaco..." Without the Queen's consent, the marriage would have been void in Britain where Ernst August's family owns property and his lawful descendants remain in succession to both the British crown and the two suspended peerages. Similarly the Monégasque court officially notified the government of France of Caroline's marriage to Ernst August, receiving assurance that there was no objection in compliance with the (since defunct) Franco-Monegasque Treaty of 1918. Moreover, in order for Caroline to retain her claim to the throne of Monaco and to transmit succession rights to future offspring, the couple were also obliged to obtain the approval of yet a third nation, in the form of official consent to the marriage of Caroline's father, Prince Rainier III as the sovereign of Monaco. Nonetheless, Caroline was a Roman Catholic and Ernst August the male heir of George III when the couple wed, at which time a provision of the Act of Settlement 1701 stipulated that in the event the British crown is to devolve upon an heir married to "a Papist", that heir is permanently disabled from succeeding to the throne, which would pass instead to the next Protestant in the order of succession who had not been married to a Roman Catholic. The Succession to the Crown Act 2013 repealed that marital restriction (also embodied in the Bill of Rights 1689), with retroactive effect, as of 26 March 2015. Ernst August's younger brother Prince Ludwig Rudolph of Hanover and his wife, Princess Isabella of Hanover (1962–1988), died tragically. On 28 November 1988, while authorities removed Princess Isabella's body from "The Queen's Villa" in Gmunden, Austria, a house owned by Ernst August which he had left to his brother and sister-in-law, and investigated the drug-strewn scene, Ludwig Rudolph, distraught over his wife's apparently accidental cocaine overdose, placed a call to his brother in London, imploring him to take care of the couple's 10-month-old son. Then he fled. Hours later Ludwig Rudolph was found dead, apparently a victim of suicide, near his family's hunting lodge several miles away, on Lake Traun. Custody of their infant son Otto Heinrich was eventually awarded, contrary to the expressed wishes of Ludwig Rudolph as the surviving parent and Ernst August's legal efforts, to the child's maternal grandparents, Count Ariprand (1925–1996) and Countess Maria von Thurn und Valsassina-Como-Vercelli (born 1929), to be raised at their family seat, Bleiburg Castle in southern Austria.