You didn't really provide the letter out of which we should be able to deduce the benefits. However, Crusaders would say that the benefit of the crusaders were that they regained the holy land and could also profit out of this either by looting and pillaging neighbouring muslim villages or because they thought they were closer to God this way.
Answer:
See below:
Explanation:
During the times, Russia has maintained poltical control by purging party members who are not alligned with their ideaology's and by keeping other political parties away from the main ones by denying them the right to participate, therefore, holding a dominant monopoly in the political party/control center.