These two mourners at Regina's funeral are her brother-in-law and sister-in-law, Archduke Rudolf and Archduchess Anna Gabriele. Rudolf is one of the three surviving children of the last emperor of Austria, Karl I; Archduke Otto and Archduke Felix are the other two. The emperor had a total of eight children, all of whom married members of other royal and noble houses. Occasionally you'll see some of his descendants popping up in other royal families. We've already glimpsed one on the blog before -- Archduke Lorenz, the husband of Princess Astrid of Belgium, is a grandson of Karl I and the nephew of Archdukes Otto, Rudolf, and Felix.
Anna Gabriele, who is of royal descent herself, born Princess Anna Gabriele of Wrede, has chosen the suitably royal headwear option for the day -- a black mourning veil.