Grace Kelly becomes her Serene Highness Princess Grace of Monaco A fairy-tale romance story came to a climax this morning when Miss Grace Kelly became Princess Grace of Monaco. The wedding took place in the Throne Room of the Monaco Palace, the home of the Grimaldi Family for the past centuries. After the ceremony and the reception, a garden party was held and the Prince and Princess appeared to accept gifts and to accept the good wishes of the people of Monaco. Photo shows : Sitting side by side during the wedding ceremony in the Monaco Palace this morning, are Princess Grace and Prince Rainier III. 18 April 1956