On June 29, 1934, the infamous Night of the Long Knives, Hitler had Röhm, former Chancellor Kurt von Schleicher and hundreds of other problematic members of his own party murdered, in particular troublesome members of the SA.
When the 86-year-old Hindenburg died on August 2, military leaders agreed to combine the presidency and chancellorship into one position, meaning Hitler would command all the armed forces of the Reich.