The Infernal City is set after the events of The Elder Scrolls IV: Oblivion?, the latest game in the video game series, and finds the citizens of Tamriel once again facing an uncertain future. Floating high above the land is a strange and mysterious city that is casting a horrifying shadow ? wherever it falls, people die and rise again as undead. It is up to an unlikely duo ? a seventeen-year-old girl named Annaig and the Emperor's young son, Prince Attrebus ? to rescue the kingdom from doom. Annaig and Attrebus' quest will take them through the Elder Scrolls universe and their adventure is sure to add to the series' already magnificent mythology.

So Emperor Uriel had another surviving son. Prince Attrebus.. as the above text says this takes place after Oblivion.

http://www.gamesas.com/eng/news/pressrelease_042709-3.html

Please use existing threads on the subject:

http://www.gamesas.com/bgsforums/index.php?showtopic=984025

http://www.gamesas.com/bgsforums/index.php?showtopic=984032

No need for an additional thread.