The Soviet RDS-220 hydrogen bomb (code name Ivan or Vanya), known by Western nations as Tsar Bomba (Russian: Царь-бо́мба, tr. Tsar'-bómba, IPA: [t͡sarʲ ˈbombə], lit. Tsar bomb), allegedly was the most powerful nuclear weapon ever created. Tested on 30 October 1961 as an experimental verification of calculation principles and multi-stage thermonuclear weapon designs, it also remains the most powerful explosive ever detonated. It was also referred to as Kuzma's mother (Russian: Ку́зькина ма́ть, tr. Kúz'kina mát', IPA: [ˈkusʲkʲɪnə ˈmatʲ]), possibly referring to First secretary Nikita Khrushchev's promise to "show the United States a Kuzma's mother" (an idiom roughly translating to "We'll show you") at a 1960 session of United Nations General Assembly.
The bomb had a yield of 50 megatons of TNT (210 PJ). In theory, it would have had a maximum yield of 100 megatons of TNT if it had included a uranium-238 tamper, but because only one bomb was built, this was never demonstrated. The single bomb was detonated at the Sukhoy Nos cape of Severny Island, part of Novaya Zemlya.