Conversation so far:
When did Grigori Rasputin rise to prominence?
Word of Grigori Rasputin's activity and charisma began to spread in Siberia during the early 1900s.

Question: Which names are worth mentioning in his breakthrough?
Self-contained rewrite: Which names are worth mentioning in Grigori Rasputin's breakthrough when word of Rasputin's activity and charisma began to spread in Siberia during the early 1900s?