Namesakes
Notable Philosophers and Thinkers:
1 linguist
L. L. Zamenhof (a.k.a. Ludwik) 1859-1917 
Olympic Medalists:
1 gold
(gold) Zdzisław Krzyszkowiak (middle name Ludwik) 1960 3000 m steeplechase
Polish High Dukes and Kings:
1 king
King Ludwik I 1370-1382