 He also has two half siblings, Tiffany, from his father's marriage to Marla Maples, and Barron, from his father's current marriage to Melania Trump.Through his father, Trump Jr. is a grandson of Fred Trump and great-grandson of Elizabeth Trump, who founded what became the Trump Organization.As a boy, Trump Jr. found a role model in his maternal grandfather, Miloš Zelníček, who had a home near Prague, where he spent summers camping, fishing, hunting and learning the Czech language.