Conversation so far:
What book did Sven Hedin write?
In his book Från pol till pol, Hedin describes a journey through Asia and Europe between the late 1880s and the early 1900s.
What country did Sven Hedin want to join forces with?
He warned of the dangers he assumed to be coming from Czarist Russia, and called for a Swedish alliance with the German Empire.

Question: When was he born?
Self-contained rewrite: When was Sven Hedin born?