Moravec selected two dozen recruits to undertake commando training at an SOE base in Scotland. Jozef Gabčík and Jan Kubiš were selected to carry out the attack. On 28 December 1941 the men were dropped into Czechoslovakia.
In Prague, they made contact with the resistance, but local groups were opposed to the plan for fear of reprisals.
Gabčík and Kubiš initially planned to kill Heydrich on a train, but then realised that was not going to be possible. Then they considered killing him on a forest road that led from Heydrich’s home to Prague but that too was discounted. Finally it was decided to kill him in Prague.
At 10:30 on 27 May 1942, Heydrich began his journey to his headquarters at Prague Castle. Gabčík and Kubiš waited at a tram stop en route close to a tight curve where they knew the car would have to slow down. As Heydrich’s open-topped Mercedes reached the curve Gabčík stepped in front of it and tried to fire his Sten submachine gun, but it jammed. Kubiš then threw a modified anti-tank grenade (concealed in a briefcase) at the rear of the car. It detonated, wounding Heydrich. Kubiš was also injured by the shrapnel.
Heydrich staggered out of the car, apparently unaware of his injuries; Gabčík and Kubiš fired at him with their pistols but both missed. They both then fled.
Heydrich was helped to a nearby hospital where it was found that he had suffered severe injuries to his left side, with major damage to his diaphragm, spleen and lung. He was operated on.
It was initially thought that he was recovering but on 9 June he collapsed while sitting up eating a noon meal and went into shock. He spent most of his remaining hours in a coma and never regained consciousness, dying around 04:30 the next morning.
Hitler ordered an investigation and reprisals on the day of the assassination attempt, suggesting that Himmler dispatch SS General Erich von dem BachZelewski to Prague, a man thought to be even harsher than Heydrich. More than 13,000 people were arrested and an estimated 5,000 people were murdered in the reprisals.
The search for the culprits continued. Intelligence falsely linked the assassins to the village of Lidice and so on 9 June 1942, the Germans committed the Lidice massacre. 199 men were killed, 195 women were deported to a concentration camp and 95 children taken prisoner. Of the children, 81 were later killed in gas vans.
The Czech village of Ležáky was also burnt to the ground, with both men and women murdered.
Eventually Gabčík and Kubiš were betrayed by a fellow resistance fighter Karel Čurda, who gave the Gestapo their location (and that of several other safe houses) in return for one million Reichsmarks.
On 17 June an operation against Gabčík and Kubiš began when 750 SS troops laid siege to a church where the two were hiding out. After a two-hour gun battle Kubiš was shot dead and Gabčík and three others committed suicide. Bishop Gorazd took the blame for the actions in the church, to minimise the reprisals among his flock. He was arrested, tortured and then killed.
The assassination of Heydrich was one of the most significant moments of the Czech resistance and it led directly to the abandonment of the Munich Agreement by France and Britain, ensuring that after the war the annexed territory of Sudetenland was restored to Czechoslovakia. Karel Čurda was hanged for high treason in 1947.