Year 928 (CMXXVIII) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
- King Rudolph I loses the support of Herbert II, count of Vermandois, who controls the prison at Péronne in which former King Charles III (the Simple) is imprisoned. Herbert brings him before William I (Longsword), count of Rouen, for homage and then to Rheims as leverage to blackmail Rudolph to make him cede sovereignty over Laon (Northern France).
- June 5 – Louis III (the Blind), former king of Provence (Lower Burgundy), dies at Arles after a 27-year reign (of which 23 are sightless). He is succeeded by his brother-in-law Hugh I who is King of Italy. With the approval of his kinsman Rudolph I, Hugh strips Louis's son and heir, Charles Constantine, of his inheritance and proclaims himself as ruler of Provence.
- Winter – King Henry I (the Fowler) subdues the Polabian Slavs who live on the eastern borders. He then marches against the Slavic Hevelli tribes and seizes their capital, Brandenburg. Henry invades the Glomacze lands in the middle Elbe valley, where he besieges and destroys the main castle called Gana (the later Albrechtsburg) at Meissen (Saxony).
- Summer – An Arab expeditionary force led by the Slavic Sabir returns and seizes Otranto (Southern Italy). Although pressed by an epidemic, they withdraw their forces. After capturing some enclaves on the Tyrrhenian coast, Sabir sails into the harbors of Naples and Salerno, and forces the dukes (dux) to pay an enormous sum of tribute to go away.