Question:  The leader of the Crimean Karaites followed Şahin Giray to what protectress who was the country's longest-ruling female leader and arguably its most renowned?
Sentence (from "Benjamin Aga"): Through the intervention of Count Nikolay Zubov, the delegation obtained from the empress the exemption from the "Jewish" taxes, some land grants, and other privileges which had not been asked for.
Relevant evidence: No