Final answer:
The biggest influencer of Byzantine/Greek culture on Russia was the spread of Orthodox Christianity.
Step-by-step explanation:
The biggest influencer of Byzantine/Greek culture on Russia was the spread of Orthodox Christianity. When the Byzantine Empire converted to Christianity in the 4th century, they adopted the Eastern Orthodox branch of Christianity, which they then introduced to the Slavic peoples of Russia through missionary work. As a result, Russia adopted the Orthodox faith as well as many Byzantine artistic and architectural styles.
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