Terenas Menethil II was the last true king of Lordaeron and the primary founder of the original Alliance of Lordaeron. Terenas refused to listen to the wisdom of the prophet Medivh (The Last Guardian). Terenas was later killed by his son Arthas after his campaign in Northrend.
In the opening and ending cinematic for the human campaign in the video game Warcraft III: Reign of Chaos the voice actor for Terenas was uncredited.
For the longest time no one knew who voiced the character. Even now I'm not 100% sure but after researching and finding some minor sources I believe that Tony Jay voiced the character before his death.
For the opening cinematic narration and the game play for the video game World of Warcraft: Wrath of the Lich King Earl Boen voices the character.