Johann Nepomuk Hiedler , also known as Johann Nepomuk Hüttler ( 19 of March of 1807 – 17 of September of 1888 ) was the maternal great – grandfather and possibly also the paternal grandfather of Adolf Hitler . Johann Nepomuk received his name from the bohemian saint of John Nepomuk (Johann Nepomuk in his language). Some see this name as proof that Johann Nepomuk and later his great-grandson Adolf Hitler had some Czech blood . However, Johann von Pomuk / Johann Nepomuk, was an important saint for bohemians of the different German and Czech ethnicities. The use of Nepomuk simply indicates links with Bohemia, with no indication of their ethnic origin. Johann Nepomuk became a relatively prosperous farmer and was married to Eva Maria Decker (1792-1888), who was fifteen years his senior. On January 19, 1830, Hiedler gave birth to Johanna Hiedler . Legally, it was the uncle of Alois Schicklgruber (later Alois Hitler), the stepson of his brother Johann Georg Hiedler , errant miller. For unknown reasons, Johann Nepomuk adopted Alois as a child and raised him. It is possible that he was, in fact, the biological father of Alois, but could not acknowledge it publicly because of his marriage. Another, and perhaps simpler, explanation for this kindness is that Johann Nepomuk took pity on the ten-year-old Alois and raised him. Alois was, after all, the step-son of his brother Johann Georg, and Johann Nepomuk may have known that, in fact, Alois was the natural son of Johann Georg. After the death of Alois’ mother, Maria Schicklgruber , it could hardly have been a life for a ten-year-old child to be raised by an itinerant miller. In any case, Johann Nepomuk left Alois a considerable part of his savings. Johann Nepomuk’s granddaughter , Klara Pölzl (daughter of Johanna Hiedler ), had a long-standing affair with Alois before marrying him in 1885 after the death of his second wife. In 1889 gave birth to Adolf Hitler .