Shalidor was a male Nord. Shalidor is the famous Archmage of the First Era who created the Labyrinthian in Skyrim. The Labryinthian is known as the Archmage's testing ground and it still exists at the beginning of the Fourth Era. According to Urag gro-Shub, while Shalidor was in Labyrinthian, he heavily studied magic and the arcane arts, researching, writing and experimenting more than anyone could imagine possible. The great maze is also used to keep an artifact called Glamoril. Shalidor himself lived in a citadel called the Fortress of Ice.
Shalidor once fought the Dwemer of the Rourken Clan. The Rourken Clan was one of the Dwemer Clans that refused to make peace with the Chimer in the forming of the First Council. Instead, they exiled themselves from Morrowind, and moved to the west, to Hammerfell. It's possible that during the long march to Hammerfell, the Rourken Clan clashed with Archmage Shalidor in the Battle of Rourken-Shalidor. The artifact Spellbreaker is a powerful Dwemer shield that was used during the battle. The shield is able to reflect magicka and silence any nearby mage.
The Archmage Shalidor was well known for his spell Shalidor's Mirror, which he used to reflect an offensive spell back to the caster. Some other scholars speculate that Shalidor, after the battle with the Rourken Clan, tried his best to find the exact magical effect of the Spellbreaker, from his research Shalidor's Mirror was born.
Most of the research and writings that Shalidor wrote while in Labyrinthian were lost to time and space, but some of what he wrote is still out there, and would be extremely valuable to any and all arcane universities. Many of these arcane colleges such as the The College of Winterhold attempt to seek out more of Shalidor's writings to expand the The Arcaneum, improve the arcane skills of the members there and to help the college expand and improve as a whole. 
- ↑ The Elder Scrolls V: Skyrim