The Third Great Earth-Romulan War was a war fought between the Federation and Romulan Star Empire prior to 2525. The results of this war are not known although it is likely the Federation won. According to Zak Kebron the war was caused by the Romulans discovering that the assassination of Senator Merken Vreenak was carried out by the Federation, not the Dominion. (NF short story: "Stone Cold Truths")