Namesakes
Characters in Norse Mythology:
1 character
Sigmund (m) 
Notable Philosophers and Thinkers:
1 psychologist
Sigmund Freud 1856-1939
Polish High Dukes and Kings:
1 king
King Zygmunt III Vasa (a.k.a. Sigmund) 1587-1632
Rock and Roll Hall-of-Famers:
1 musician
Jackie Jackson (a.k.a. Sigmund) 1997 The Jackson 5
Swedish Kings and Queens:
1 king
King Sigismund (a.k.a. Sigmund) 1592-1599