 Princess Antoinette then threw her full support behind the succession of her brother.The family presented a unified front thenceforth, with Prince Rainier III granting his sister the title of Baroness of Massy, and young Christian de Massy serving as ring bearer at the marriage of his uncle to Grace Kelly.Referred to since childhood as "Baron de Massy", including during the lifetime of his mother the Baroness, Christian's use of the title became official in 2009, two years before his mother's death in 2011.