Regent

Regent is the title held by someone who rules in name of the King or a Lord because the ruler is a child or incapacitated.

If the Regent rules in the name of the King of the Andals and the First Men, he or she also hold the title of Protector of the Realm. The Regent also holds a seat in the small council.

Known Regents

 * Lady Lysa Arryn, ruling as Lady Regent of the Vale in name of her son Robin Arryn.
 * Lord {Eddard Stark}, Lord of Winterfell, Warden of the North and Hand of the King, declared Regent and Protector of the Realm by Robert Baratheon in his will to prevent Queen Cersei from seizing power. Ned, however, was betrayed, arrested and executed for treason and never assumed the Regency.
 * Queen Cersei Lannister, currently sharing power with her son, King Joffrey Baratheon.