The most prominent House before the Regency era. It played a key role in the history of the Known Worlds but its power peaked at the start of the Empire after which it quickly dissolved.
House Alecto can trace its origins back to Greek and Roman Urth origins. During the Diaspora its noble Palamedes Alecto formed the Celestial Church from the Prophet's followers. As the Second Republic fell and Byzantium Secundus was invaded Alecto played a leading role in the Royal Ten.
And it was during the barbarian invasions Vladimir Alecto united the houses in a raid on the barbarians. After which Vladimir formed the Empire, including the Imperial Eye.