Alera is the setting of most of the Codex Alera books. It is an empire that is ruled by a First Lord, along with High Lords ruling the various cities. The people of Alera have the capability to control the elements by bonding with beings known as furies.Their civilization is based on the Roman Empire. In its history it has beaten and destroyed numerous enemies including but not limited to, the Children of the Sun, the Malorandim, the Avar, the Yrani and the Dekh.
The land and nation of the Alerans, it constitutes most of a continent, ending at the coast to the west and south, the Calderon Valley land bridge to the realm of the Marat, Maratea, to the east, and the Shieldwall to the north.
The nation is divided into state-like territories named for the prominent cities, each ruled by a High Lord. Inside these territories exist various towns and steadholts (villages) where the majority of the free, non-citizen populace live. Each city fields the Legions that make up the military of Alera. These cities, and their lords at the start of the series, are:
- Alera Imperia, ruled by the First Lord Gaius Sextus and First Lady Gaius Caria
- Antillus, ruled by High Lord Antillus Raucus and High Lady Antillus Dorotea
- Aquitaine, ruled by High Lord Aquitainus Attis and High Lady Aquitainus Invidia
- Attica, ruled by High Lord Atticus Quentin
- Ceres, ruled by High Lord Cereus Macius
- Forcia, ruled by High Lord Forcius
- Kalare, ruled by High Lord Kalarus Brencis
- Parcia, ruled by High Lord Parcius
- Placida, ruled by High Lord Placidus Sandos and High Lady Placidus Aria
- Phrygia, ruled by High Lord Phrygius Guntus
- Rhodes, ruled by High Lord Rhodes Martinus
- Riva, ruled by High Lord Rivus Grantus