Short answers, pulled from the story.
Lev Semyonovich Vygotsky was born on the 17th of November 1896 in Orsha within the Mogilev Governorate. He grew up in Gomel where he received home schooling until 1911 before entering a private Jewish gymnasium.
Vygotsky participated in the Second All-Russian Psychoneurological Congress held in Petrograd during January 1924 which led Alexander Luria to invite him as a research fellow at the Psychological Institute in Moscow. He moved to Moscow with his new wife Roza Smekhova after this meeting.
The term zone of proximal development describes an individual's mental growth potential sitting between their current ability and achievable level with assistance from others. This concept defines the lower limit as skill reached independently while the upper limit reflects potential with help from a more knowledgeable other.
Lev Vygotsky died of a relapse of tuberculosis on the 11th of June 1934 at age thirty-seven in Moscow. He had been hospitalized in the Zakharyino sanatorium-type hospital from the 21st of November 1925 until the 22nd of May 1926 due to his illness.
The Communist Party condemned pedology or developmental psychology in 1936 following increased repression against non-Marxist psychology. His early death coincided with Joseph Stalin's Great Purge which turned his theories into real heresy during that period.