The mighty Orsinium had become a threat to the neighboring kingdoms. In 1E 948 King Jolie of Daggerfall sent a letter to Gaiden Shinji of the Order of Diagna, proposing a joint attack on Orsinium. After King Golkarr praised the raiders terrorizing the Bjoulsae River, an alliance was formed, and this effectively reduced the feud between Redguard and Breton. Now both races had focused on a single common foe, the Orcs and beast folk of Orsinium.
The Bretony forces of Daggerfall, the Redguard army of Sentinel, and the Order of Diagna joined forces to invade Orsinium. However, the Orcish Kingdom of Orsinium proved to be too powerful. The Siege of Orsinium took a long 30 years, consuming great warriors and heroes. Among them was Gaiden Shinji himself. To this day, the Orcs are still renowned for their battle prowess.
The forces of Sentinel were significantly weakened by the Orcs, even more so than their allies. Daggerfall seeing this weakness invaded Bankorai Pass, a strategic mountain pass that connecting High Rock to Hammerfell (formerly Volenfell).