The relationship between Hitler and his father, such as it was, could be described as minimal, if not nonexistent. His father, Alois, had been married twice before. When his second wife was seriously ill, he had an adulterous relationship with her nurse, Klara, who was later Hitler's mother. He married her before Hitler was born and had an older child by her before his second wife died.
Alois was a distant man at best, who believed in whipping his children for the slightest offense, which he believed would teach them discipline. He never called Hitler by name; rather when he summoned him, he did so by whistling, as one would call a dog, by placing two fingers in his mouth and uttering a loud whistle. One gets an idea of his sternness from a line which appeared in Alois' obituary:
The harsh words that sometimes fell from his lips could not belie the warm heart that beat under the rough exterior.
Alois Hitler died when Adolf Hitler was only thirteen. There is some argument that the younger Hitler was genuinely grieved when his father passed; although it had little effect on his adult life. As an adult, he seldom made reference to Alois; at such times as he did, he referred to him as "the old man." Alois did leave his family well provided for, including his son, who received enough money to last him for several years, although he spent most of it pursuing a career as an artist which was not to be.
Klara Hitler often stood up to Alois and defended her son, one of only two children who lived into adulthood. It is perhaps for this reason that Hitler had an obsessive love of his mother throughout his life. When he committed suicide, he had her picture on his bedside table.