Guardian Angel were a group from Athens that it hade been formed in the early 90s or much better in the end of 80s. They are regarded as one of the greatest greek bands. In 1990 they released their first demo Travelling By The Wings Of Eternity which left many people surprised by its two songs. Through years the name of the band was the main theme of discussions in the community of underground metal. In 1994 they recorded their second work, a single called Beyond The Twilight and suddenly things went to the best for the band. If the demo was an interesting endeavor, the single was something excellent! In 1997 the band decided to leave behind the style of heavy/power metal and have as a new ont the progressive. Their new EP Oblivion Seas made some of their funs dilike it because Guardian Angel became known by playing power. The point is that this band did something that other bands could not do and this is playing progressive metal. In 1999 they released their last demo and after that till today they have remained split-up.

Source : http://hellenicmetal.blogspot.com/2008/04/guardian-angel.html