Namesakes
Pedro de Sousa Holstein
(m) 1781-1850 
Portuguese Presidents and Prime Ministers 1834-1835; 1842; 1846 (prime minister)
Ludvig Holstein-Holsteinborg
(m) 1815-1892
Danish Prime Ministers 1870-1874
Ludvig Holstein-Ledreborg
(m) 1839-1912
Danish Prime Ministers 1909