A Jarl is a ruler of one of the nine holds of Skyrim, equivalent to a Count. The jarls of Skyrim are largely independent, though they all swear fealty to the High King. All jarls have their own personal housecarl and steward, and some also have one or more thanes in their service. Many also have a court wizard in their service who is also sometimes the only spell merchant in town.
The game begins with nine jarls ruling the holds of Skyrim, each affiliated with either the Imperial Legion or the Stormcloak Rebellion. All except Elisif the Fair can be supplanted by a new jarl who is more supportive to the opposing force, based on your actions during the game. This depends on which force you choose to ally with in the civil war, and jarls will be replaced when you help a side to capture a city they do not control, or through the negotiations made during Season Unending. Newly-instated jarls will gain a "Jarl" prefix to their name and move into the jarl's residence for that hold.
Deposed Imperial governments will generally seek refuge in the basement of the Blue Palace in Solitude, while deposed Stormcloak governments will go into exile in the Palace of the Kings in Windhelm. Only the jarl, their housecarl, and their steward will be evicted from the building, and they will act unfriendly towards you.
Several jarls, however, will go elsewhere if they are ousted from government. Jarl Korir and his family will move into Brunwulf Free-Winter's House in Windhelm and Dengeir of Stuhn will go to Candlehearth Hall. Brina Merilis will move to The Winking Skeever in Solitude and Kraldar will move into Erikur's House. Maven Black-Briar will simply return to her home in Riften, as will Sorli the Builder to Stonehills if either jarl is removed.
 Jarls of Skyrim
- The jarl of the Pale (either Skald or Brina Merilis) does not have a steward.
- Strangely, a deposed jarl's family will not be ejected from the jarl's residence with them. The family will continue to live in the same residence with the new occupants and never even acknowledge that anything has changed (except for the family of Morthal's jarl).
- Even if you cede control of a city to an opposing faction during the negotiations in Season Unending, both the previous and new jarl will recall a big battle for the city, despite no such battle ever taking place.
- Jarl Korir of Winterhold does not have a court wizard, likely due to his ire towards wizards due to "The Great Collapse".
- Jorleif does not give up his duties as steward after the Battle for Windhelm, but he will still show resentment towards you.
- If you join the Stormcloaks, then Elisif the Fair will renounce her support for the Imperial Legion and will support the Stormcloaks, even though the jarls that supported the Legion are exiled to the Blue Palace.
- Erikur, Bryling and Hrongar were originally intended to become jarls, and still remain in the jarl faction. Erikur was to replace Elisif the Fair, who was to be murdered in Boethiah's Bidding. Bryling would have served as his replacement should the Stormcloaks capture Solitude. Hrongar was to replace Balgruuf the Greater after the latter was killed by his children during The Whispering Door. Somehow killing the incumbent jarls can trigger dialogue referencing the scrapped quests.