'Silver A' was a British and Czechoslovak special forces operation to parachute a three-man team into the Kolin area to establish liaison with the resistance forces in German-occupied Czechoslovakia (28 December 1941/2 July 1942).

This was the fourth in a series of operations by the D Branch (intelligence) of the Czechoslovak government-in-exile’s war office in London, and was prepared and implemented with the assistance of the Royal Air Force.

The three-man team comprised Lieutenant Alfréd Bartos (commander), Sergeant Josef Valčík (deputy commander) and Sergeant Jiří Potůček (radio operator), and was tasked to arrive in occupied Czechoslovakia by parachute and establish and maintain radio communications with London by means of a radio network codenamed 'Libuse', to establish an intelligence cell to co-ordinate the activities of other teams which were to be delivered by parachute at a later date and, most importantly, establish links with Staff Captain Vaclav Moravek of the 'Three Kings' (Tři králové) resistance group and the agent Paul Thummel, a German officer who was one of the most important local sources of information for the D Branch.

The aeroplane carrying the 'Silver A' group took off during the evening of 28 December, and the group descended into Czechoslovakia early in the morning of the following day. The originally planned landing site was near the village of Vyzice in the Chrudim area, but as a result of navigation inaccuracy the group actually landed some 25 miles (40 km) distant from this at Senice in the Poděbrad area. Valčík, the last man out of the aeroplane, lost contact with the two other members of the group, but nonetheless met the Bartos on 31 December at Mikulovice in the Pardubice area.

Bartos was able to make contact with the resistance, and thus with Vladimír Krajina of the ÚVOD (Ústřední vedení odboje domácího, or central group of home resistance) and Staff Captain Moravek of the Obec Sokol Club v odboji group in Pardubice, began to build an extensive network of operatives, which at the height of the network’s capabilities totalled more than 140 persons. With the help of the network, a number of apartments and even employment was organised for Bartos and Valčík: the latter worked as a waiter at the Hotel Na Veselce.

On 15 January 1942 Potůček, the radio operator, established a radio link with London from a quarry site at Hluboká near Miřetic in the Chrudim area. Given the constant threat of German interception and reaction, the radio station was relocated several times, the places including the fishery research station in Bohdanečský, a mill, and a school in Bohdasíně in the Červeného Kostelce area.

Moravek established contact with Paul Thümmel, and in the town of Lázně BElohrad the group established a rendezvous for later groups at a book shop.

In March 1942 the Gestapo became aware of possible intelligence activities and set a trap, but Valčík managed to escape this and was called then summoned to Prague to support the British undertaking to bomb the Skoda armament works in Plzeň. He then joined the 'Anthropoid' group and helped with the preparations for the assassination of Reinhard Heydrich.

After Heydrich’s assassination, Valčík hid with six other members of the group in the crypt of the Orthodox Church of St Cyril and Methodius, and here killed himself with his comrades on 18 June after a hopeless struggle against overwhelming strength the Germans brought to bear on the church.

In the middle of June there began a series of arrests in the Pardubice region. The Gestapo succeeded in obtaining the addresses of the safe houses used by Bartos, and in one of these apartments found Bartos’s records, which led to another wave of arrests and executions. On his return to the apartment in Smilově street in Pardubice, Bartos was trapped and realising that his situation was hopeless turned his gun on himself: mortally wounded, he was taken to hospital and died on the following day.

Potůček moved to Bohdasín and remained in contact with London until 26 June, when he took refuge at the farm of Antonín Burdycha. Here the Gestapo attempted to ambush him on 30 June, but Potůček managed to escape after an exchange of fire. He then sought refuge at several addresses, but was turned away at each of these. Exhausted, he fell asleep on 2 July in bushes near the village of Rosice nad Labem, and was shot by a Czechoslovak policeman, Karel Půlpán.

In reprisal for the 'Silver A' group’s activities, on 24 June the Germans burned the village of Lezáky and executed 37 members of the resistance from the Pardubice region and 15 from Červeného Kostelce. Among those killed were the mother and girlfriend of Bartos, and the father, mother, siblings and five other relatives of Valčík.