He was born in Halle, Germany. His father and mother were both very heavily musically involved, and Heydrich grew a passion for the violin, which was to continue through his life. His father was virulently anti-semitic, and he received frequent beatings. Although Heydrich was a shy boy, he excelled physically and grew up to be handsome and fit. He was an impressive athlete, excelling in fencing and swimming. However, young Heydrich was often taunted for his family's Roman Catholicism within a mainly Protestant community, and for rumors of a Jewish ancestry - something that was to haunt him personally and politically for much of his life, even though there was no basis in reality for it.
Heydrich had early fascinations with the extreme right and racialist ideology, participating in the freikorps when he was young. In 1922 he joined the navy, however he was later dismissed when he had a brief liason with a shipyard director's daughter, and subsequently became engaged to a young woman, Lina von Osten. The daughter told her father of her anger over the incident, and he was subsequently charged with "conduct unbecoming to an officer and a gentleman". His behaviour in court was apparently so disdainful that the court also rebuked him for insubordination. Heydrich was left with no career prospects, however, he remained engaged to von Osten, whom he married in 1931.
1931 was to be a turning point for Heydrich in another, far more important way. Himmler wished to set up a counter-intelligence division of the SS. Acting on a friend's advice, he interviewed Heydrich, and after a twenty minute test whereby Heydrich had to outline plans for the new division, Himmler hired him on the spot. In doing so Himmler also effectively recruited Heydrich into the Nazi Party.
Heydrich soon built up a fearsome reputation within the party, and in July 1932 his division took on the title of Sicherheitsdienst (SD). Heydrich soon built up a mutually beneficial partnership with Himmler, with each benefitting politically.
Heydrich helped Hitler 'dig up dirt' on many opponents, keeping an impressive filing system listing opponents to the party and the regime. Heydrich was also instrumental in establishing the false 'attack' by Poland on The German radio station, which was to be the beginnings of World War II.
Heydrich became one of the main architects of the Holocaust during the first years of World War II and chaired the Wannsee conference at which plans for the deportation of the Jews to extermination camps were discussed.
In September 1941 he was appointed Protector of Bohemia and Moravia, replacing Konstantin von Neurath who Hitler considered not harsh enough.
On May 27, 1942 he was assassinated by a team of British-trained agents of the Czechoslovak government in exile in London. The team comprised of Adolf Opalka (the leader), Josef Valcik, Jan Kubis and Josef Gabchik. Heydrich's car, driven by SS-Oberscharfuhrer Klein, had to slow down to take a sharp bend where the Czech team waited. As the car approached, Gabchik took aim and pulled the trigger of his Sten, but the gun failed and did not fire. Klein, believing Gabchik to be alone, stopped to shoot at him. Kubis then threw an anti-tank grenade at the car. This exploded and severely wounded Heydrich.
Despite Himmler sending his best doctors, Heydrich died in Prague at 4:30am on June 4 at the age of 38. Although the exact cause of death has not been definitively established, the autopsy states that Heydrich's death was most likely caused by bacteria and toxins from the bomb splinters. A highly elaborate funeral was staged for him in Berlin, with Hitler attending. Hitler himself perhaps encapsulated Heydrich best in his acknowledgement that Heydrich was partly to blame for his own death through his arrogance and blasé attitude:
"Since it is the opportunity which makes not only the thief but also the assassin, such heroic gestures as driving in a open, unarmoured vehicle or walking about the streets unguarded are just damned stupidity, which serves the country not one whit. That a man as irreplaceable as Heydrich should expose himself to unneccessary danger, I can only condemn as stupid and idiotic."
The retaliation from the Nazis was savage, a stark warning to potential copycats. On June 10 all males over the age of 16 in the village of Lidice, 22 km north-west of Prague, were murdered. Several hundred Jews were sent to extermination camps. Heydrich's eventual replacement was Ernst Kaltenbrunner.