Not quite. The R-7 development started in 1953, when the Soviets didn't even have a 1Mt weapon. At the time it was thought the smallest megaton range staged thermonuclkear bomb would be 3-6 tonnes. ergo one BFICBM needed.
The 100Mt Tsar Bomba was a later 1961 device, primarily a Kruschev propaganda display. But if it had been actually deployed, the intended range would have been much shorter - 3-5 of them airdropped (in its 50Mt sans Uranium tamper form) ahead of the advancing Warpac forces in Europe in the event of unpleasantness breaking out. The biggest bomb ever built: a tactical weapon. True story.
The program may have started in 1953 but they did not launch the first rocket until 1965
It was eventually utilized as a space launch vehicle. It was the brainchild of Vladimir Chelomei’s design bureau as a foil to Sergei Korolev’s N1 booster.With the termination of the Saturn V program, Proton became the largest expendable launch system in service until the Energia rocket first flew in 1987 and the U.S. Titan IV in 1989.