1941-1942

In the weeks before the German invasion of the Soviet Union, Timoshenko and Zhukov were worried by reports that German planes were crossing the Soviet border at least 10 times a day, and on 13 June, they asked Stalin for permission to put the troops on the western border on high alert, but were overruled because Stalin was convinced that there would be no German invasion before spring 1942.^[10]

General Ivan Boldin, deputy commander on the western front, recounted in memoirs published 20 years later that early in the morning of the invasion, on 22 June, when several towns in Belarus, including Grodno, were being bombed, aircraft destroyed on the ground, troops were being strafed, and German paratroopers were landing behind Red Army lines, Timoshenko rang him with an instruction that "no action is to be taken against the Germans without our knowledge ... Comrade Stalin has forbidden to open artillery fire against the Germans".^[11]

On 23 June, Timoshenko was named chairman of Stavka, the Soviet Armed Forces High Command.^[12] In July 1941, Stalin replaced Timoshenko as Defense Commissar and Stavka's chairman. At the same time, the Western Front was divided into three sectors, with Timoshenko put in command of the Central Front^[4] to supervise a fighting retreat from the border to Smolensk. The Northern Front was commanded by Voroshilov, and the Southwestern Front by Budyonny, both of whom were removed by Stalin after only a few weeks for incompetence.^[13] Timoshenko was transferred to Ukraine in September to replace Budyonny and restore order in the at the gates of Kiev. On 23 October, the Soviets made Timoshenko command the entire southern half of the Eastern Front and Georgy Zhukov command the northern half.^[14] In November and December 1941 Timoshenko organized major counter offensives in the Rostov region, as well as carving a bridgehead into German defenses south of Kharkiv in January 1942.^[4]

In May 1942, Timoshenko, with 640,000 men, launched a counter-offensive (the Second Battle of Kharkov) which was the first Soviet attempt to gain initiative in the springtime war. After initial Soviet successes, the Germans struck back at Timoshenko's exposed southern flank, halting the offensive, encircling Timoshenko's armies, and turning the battle into a major Soviet defeat.

The fact that he was the most senior Soviet army officer with a front line command during most of the first year after the German invasion turned Timoshenko, briefly, into an international celebrity, lionised in the USA and UK in particular as a supposed military genius. According to an account written later in the war:

Marshal Timoshenko flared up like a shooting star of unusual brightness against a sky that was more than commonly dark, and faded just as swiftly and unexpectedly. From June 1941 to about July 1942, so famous was he that foreigners, notably the Welsh and Irish, attempted to inch under his halo by finding their blood in him. The Welsh said that Timothy Jenkins was the Marshal's ancestor who had migrated to Russia to work as a mechanic and marry a Ukrainian girl. The Hibernians told a similar story about a certain Tim O'Shenko. In June 1942, an American humorist wrote: "I am waiting to hear from the Poles, the Czechs, the Brazilians and the Greeks. Everybody wants to be a winner." But just then, Marshal Timoshenko began his descent from glory.^[15]

General Georgy Zhukov's success in defending Moscow during December 1941 had persuaded Stalin that he was a better commander than Timoshenko. On 22 July 1942, Stalin replaced Timoshenko with Vasily Gordov as Commander of the Stalingrad Front due to his failures up to that point in the war,^[16] making him Chairman of the High Command. He was called back into service as overall commander of the Northwestern Front between October 1942 and March 1943.^[17]

1943-1945

Nonetheless Timoshenko continued active military action in the later phase of the war. From March 1943, he was appointed as a representative of STAVKA to coordinated the actions of a number of fronts. He took part in the development and conduct of some operations. From March to June 1943 Timoshenko coordinated the Volkhov and Leningrad fronts during the battles at the Leningrad sector. By December 1943 he coordinate the North Caucasian Front and the Black Sea Fleet, oversaw the liberation of the North Caucasus and Novorossiysk, the landing operation in Kerch Peninsula, paving the way for the liberation of Crimea later. From February to June 1944 he oversaw the actions of 2nd and 3rd Baltic fronts, including the Starorussko-Novorzhevskaya operation. From August 1944 until the end of the war he coordinate the actions of 2nd, 3rd and 4th Ukrainian fronts.^[18]

Timoshenko was awarded his first Order of Suvorov, 1st class due to the achievements in the Caucasus and the bridgehead in Crimea.^[19] After the Red Army liberate Chisinau on August 25 during the Jassy–Kishinev offensive, Timoshenko sent a telegram to Stalin which praised the achievement of the 2nd and 3rd Ukrainian fronts under his coordination and requested the promotion of their respective commanders, Malinovsky and Tolbukhin, to the rank of Marshal of the Soviet Union. The commanders were indeed promoted, and Timoshenko was also awarded another Order of Suvorov, 1st class.^[20][21] On June 4, 1945, Timoshenko was awarded the Order of Victory for his contributions in the war.

In 1945, Timoshenko attended the Yalta Conference. A rumor started in the western press that Stalin had attacked Timoshenko, but was later disproved.

Between 15 August 1945 and 15 September 1945, Timoshenko traveled alone to review the Starye Dorogi displaced persons camp where Auschwitz concentration camp survivors recuperated after their liberation. Later, author Primo Levi (Prisoner 174517) wrote in The Truce of how the extremely tall Timoshenko "unfolded himself from a tiny Fiat 500A Topolino" to announce that the liberated survivors would soon begin their final journey home.^[22]