Johann Nepomuk Hiedler, also known as Johann Nepomuk Hüttler (19 March 1807 – 17 September 1888), was a maternal great-grandfather and possibly also the paternal grandfather of Adolf Hitler.Johann Nepomuk was named after the Bohemian Saint Johann von Nepomuk.
Some view this name as evidence that Nepomuk and subsequently his great-grandson Adolf Hitler had Czech ancestry.
However, Johann von Pomuk/Johann Nepomuk, was an important saint for Bohemians of both German and Czech ethnicity.
Nepomuk thus only indicates ties to Bohemia and central Europe.
Nepomuk became a relatively prosperous farmer and was married to Eva Maria Decker (1792–1873) who was fifteen years his senior.
On 19 January 1830, Eva Hiedler gave birth to Johanna.
Legally, he was the step-uncle of Alois Schicklgruber (later Alois Hitler), the stepson of his brother Johann Georg Hiedler, a wandering miller.
For reasons unknown, Johann Nepomuk took in Alois when he was a boy and raised him.
It is possible that he was, in fact, Alois' natural father but could not acknowledge this publicly due to his marriage.
Another, and perhaps simpler, explanation for this kindness is that Nepomuk took pity on the ten-year-old Alois and took him in.
Alois was, after all, the stepson of his brother Johann Georg, and Nepomuk may have known that in fact Alois was Johann Georg's natural child.
After the death of Alois' mother Maria, it could hardly have been a suitable life for a ten-year old child to be raised by an itinerant miller.
Nepomuk left Alois a considerable portion of his life savings.
Nepomuk's granddaughter, Klara, had a longstanding affair with Alois before marrying him in 1885 after the death of his second wife.