Ealhmund was King of Kent in 784.
The only contemporary evidence of him is an abstract of a charter dated in that year, in which Ealhmund granted land to the Abbot of Reculver. By the following year Offa of Mercia seems to have been ruling directly, as he issued a charter without any mention of a local king.
There is a general consensus that he is identical to the Ealhmund found in two pedigrees in the Winchester (Parker) Chronicle, compiled during the reign of Alfred the Great. The genealogical preface to this manuscript, as well as the annual entry (covering years 855?859) describing the death of Ęthelwulf, both make king Egbert of Wessex the son of an Ealhmund, who was son of Eafa, grandson of Eoppa, and great-grandson of Ingild, the brother of king Ine of Wessex, and descendant of founder Cerdic,[4] and therefore a member of the House of Wessex (see House of Wessex family tree). A further entry has been added in a later hand to the 784 annal, reporting Ealhmund's reign in Kent.
Finally, in the Canterbury Bilingual Epitome, originally compiled after the Norman conquest of England, a later scribe has likewise added to the 784 annal not only Ealhmund's reign in Kent, but his explicit identification with the father of Egbert. Based on this reconstruction, in which a Wessex scion became king of Kent, his own Kentish name and that of his son, Egbert, it has been suggested that his mother derived from the royal house of Kent, a connection dismissed by a recent critical review. Historian Heather Edwards has suggested that Ealhmund was probably a Kentish royal scion, whose pedigree was forged to give his son Egbert the descent from Cerdic requisite to reigning in Wessex (wikipedia)