After the first launch of a russian satellite with Sputnik-1 in 1957, during the geophysicalic year and the first launch of the US satellite Explorer-1 in 1958, the soviets have been the first nation which brought the first human being, Yuri Gagarin, in to space and successful back to Earth. after one full orbit.
That event was the beginning of the manned spaceflight and the famous Wostok Program, a spaceship for one cosmonaut.
In the program has been involved 6 launches from Wostok 1 to Wostok 6 with Valentina Tereschkowa, the first woman in space and last Wostok flight.
The next step for the Sovietunion was the Woshod Program, a spaceship for two or even three cosmonauts.
On the long run both countries , Russia and the US started in that time the competion by reaching first the Moon with a manned spacecraft.
The spacecraft for the Wostok Program was the SL 6 Wostok spcacecraft.
Responsible for the russian programs of different spaceships has been Sergej Koroljow.
All the first launches of Sputnik, Wostok, Woshod spaceships have been carried out from the Kosmodron in Leninsk what was a top secret area and located around 350 km far from Baikonur which was mentioned at that time as the launch area.
Only after 1997 Leninsk was renamed to the Kosmodron Baikonur.
Due to the top secret launches in Leninsk, the official covers for launches of the first spaceships have carried out the official cancels from Kiew or Moscow postamt.
The Kiew postamt cancel was the one which was really used at the right launch day 12th of april 1961.
The cancels from Moscow have been only used 13th or even 14th of april 1961.
Only some people knew at that time this actions so that the first dated 12th of april 1961 cancels are very rare and only availible from Kiew.
For Gagarins flight there exist two Kiew cancels one in red and one in black.
The red one have been used only for 1,5 hours at the Kiew postamt due to the flight time of Wostok 1.
This red Kiew cancel is very rare.
For further very detailed informations pls see the excellent research wirk from Dieter Falk
Wostok 1 launch 12.04.1961 Yuri Gagarin (USSR)
first man in space and spaceorbit
Wostok 2 launch 06.08.1961 German Titow (USSR)
second man in space
Wostok 3 launch 11.08.1962 Adrian Nikolajew (USSR)
first groupflight with Wostok 4
Wostok 4 launch 12.08.1962 Pawel Popowitsch (USSR)
first groupflight with Wostok 3
Wostok 5 launch 14.06.1963 Valeri Bikowski (USSR)
second groupflight with Wostok 6
Wostok 6 launch 16.06.1963 Valentina Terschkowa (USSR)
first woman in space, groupflight with Wostok 5