However, whether Hiedler was in fact Hitler's biological paternal grandfather remains disputed by modern historians.
[1] On 10 May 1842, Hiedler married Maria Schicklgruber and became the legal stepfather to her illegitimate five-year-old son, Alois.
[6] Johann Georg Hiedler is one of two people most cited by modern historians as having possibly been the actual paternal grandfather of Adolf Hitler.
But he thought it unlikely because, "from his entire demeanor, the fact that Adolf Hitler had no Jewish blood coursing through his veins seems so clearly evident that nothing more need be said on this.
"[8] Given that all Jews had been expelled from the province of Styria (which includes Graz) in the 15th century and were not allowed to return until the 1860s, decades after Alois' birth, scholars such as Ian Kershaw and John Toland dismiss as baseless the Frankenberger hypothesis, which before had only Frank's speculation to support it.