Carloman of Bavaria revolts against his father Louis the German, king of East Francia, and tries to extend the territory under his control, but is defeated in 862.

The birth date of Carloman, whose mother is Emma, daughter of the count Welf, is unknown, but was probably around 830.

His naming can be connected to his father's push to rule Alemannia around the time of his father's assembly of Worms in 829.

The first Carolingian dynast named Carloman had ruled Alemannia in 741–48, and subjugated it to the Franks.

Carloman had been old enough to participate in the civil war of 840–43, waged between his father and his uncles, Lothair and Charles the Bald.

His first record public appearance is as the leader of an army of reinforcements from Bavaria and Alemannia which he brought to his father at Worms in 842.

He subsequently led them in battle alongside his father and uncle (Charles the Bald) against his other uncle (Lothair).

It was the beginning of a warlike career.

Notker of Saint Gall, who bewailed the decline of the dynasty a generation later, called Carloman bellicosissimus (literally "most warlike").

Carloman had been present at his father's council in Regensburg, where the Slavic commander (dux) Pribina had been rewarded for his service in defending the Bavarian frontier in October 848.

In the charter confirming the grant, Carloman had signed his name first among the secular magnates (after the ecclesiastics).

Carloman had had a liaison with Liutswind, daughter of the Bavarian count Ratolt and sister-in-law of Count Sigihard of the Kraichgau.

This was Carloman's first politically independent action, and it confirms his close connection to Bavaria.

Liutswind had borne him a son, Arnulf, around 850.

This name was chosen because it was distinctly dynastic (the founder of the Carolingian family was Bishop Arnulf of Metz), yet had never been used by a reigning king and was thus appropriate for an illegitimate eldest son.

The choice of the name is the surest evidence that Liutswind and Carloman were not legally married.

Louis had first associated Carloman with his rule by appointing him prefect to the march of Pannonia, the Bavarian borderland fronting Great Moravia and Pannonian Croatia, in 856. 

He did not give Carloman the traditional prefect's seat at Tulln in Pannonia.

Instead, according to the Annales Fuldenses (863), he was given the title "prefect of the Carantanians" (praelatus Carantanis) and posted further south, in a more peripheral region, perhaps in a design to keep him from trying to seize power from his father.

Carloman and his younger brother Louis have been occasional witnesses to their father's charters since 857.

Arnulf and his cousin, Hugh, Louis's illegitimate son, were both in Koblenz around 860 at the court of their grandfather, who was probably overseeing their military education and also holding them to ensure the good behavior of their fathers.