In August 1915, a massive steel armored vehicle, weighing about 60 tonnes and mounted on two 9-meter wheels, became stuck in a marsh north of Moscow. This vehicle, known as the Tsar Tank, was the largest armored vehicle in history at the time. It never emerged from the marsh and remained trapped until 1923, when it was scrapped on site. The Tsar Tank is 18 meters long and 9 meters high, with a weight of approximately 60 tonnes. A small spring-powered model was presented to Tsar Nicholas II in February 1915, which reportedly unlocked more than 200,000 roubles of budget for the project. The inadequate steering wheel sank during the first test on August 27, 1915, in the marsh. The machine remained stuck for eight years before being cut up on site for scrap metal in 1923. The idea for the Tsar Tank came from Nikolaï Lebedenko, head of the experimental laboratory of the Russian Ministry of War. His inspiration, as he himself admitted, was the araba, a cart with large wheels that could easily pass over bumps and ditches. If a cart can do it, why not an armored vehicle? A spring-powered model was presented to Nicholas II at the beginning of 1915. During an audience on February 8, the small machine that runs on the carpet enchanted the emperor. He doubled the bet: according to sources, the project received 210,000 roubles, or even 250,000. This budget, approximately 125,000 dollars at the time, was colossal for a prototype that had only passed through stacks of books. On paper, the machine impresses. It is 18 meters long and 9 meters high, for a crew of about ten men. A fixed casemate, perched at the height of a two-story house, is supposed to accommodate a machine gun or a cannon. Sources differ on the motorization (two Maybach engines of 240 horsepower for some, two Sunbeam engines of 250 for others), but not on the principle: one engine per large wheel. The parts were manufactured in a factory in the Khamovniki district of Moscow, then assembled from the end of spring to the end of summer 1915 near the Orudyevo station, next to Dmitrov. The construction took place in the greatest secrecy. On August 27, 1915, the tests began quite well. The tank advanced on a log road laid on a swamp, crushed a tree, then left the path to enter the flooded area. That is where everything was decided. At the back, the 1.5-meter steering wheel carried a too heavy part of the mass, poorly distributed, with a diameter difference much too large between the wheels. It sank, and the colossus remained trapped from its first test. Between 9 meters and 1.5 meters, the ratio was one to six. No one managed to free the machine, and the project did not survive this failure. It was abandoned in 1915, the machine being considered underpowered and too vulnerable to artillery. The tank thus remained where it got stuck, while the war and the 1917 revolution occupied minds and resources. In 1923, after eight years spent in the forest, it was cut up on site to recover the metal. The Tsar Tank relied on size to cross obstacles. The British chose the opposite: tracks that distribute the weight over a long surface on the ground. Their first Mark I tanks entered action on the Somme in September 1916, barely a year after the failure at Orudyevo. Lebedenko, however, did not witness the end of his machine. He left Russia for the United States in the autumn of 1917, and nothing is known of what happened afterward. A page from the Moscow city museum says he was born in 1879 and died in 1948. He would thus have lived more than thirty years after the failure of his colossus.