c.575. Irminric king of Kent
Frankish princess Bertha marries Æthelberht of Kent
580s (?). Æthelberht becomes king of Kent

Little is known of Irminric's reign, indeed his name comes down to us only as that of the father of Æthelberht. The name is interesting because its first element is otherwise almost unheard-of among the Anglo-Saxons, but quite common among the Franks (see Brooks, p.64). This may suggest Frankish influence on Kentish affairs, or at the very least a lively interest in Kent in things Frankish (see entry on c.548).

Though the dates of Irminric's reign are unknown, the contemporary Historia Francorum of Gregory of Tours suggests he was ruling in about 575. In book IV, written between 575 and 581, Gregory notes that the Frankish king Charibert (561-7) married Ingoberga, and that they had a daughter who married a man from Kent (HF, IV.26). In book IX, Gregory reports Ingoberga's deathbed will (of 588-9), which states that she had a daughter who married the son of a king in Kent (HF, IX.26). It is normally assumed that this daughter is the Bertha who married Æthelberht of Kent. If so, Æthelberht was presumably not yet king, only a son of a king, at the time of the marriage, which had happened by 575?581 when Gregory mentions it. (Since Bertha can only have been born in 561?568, the marriage probably took place in the second half of the 570s, not long before Gregory recorded it.) It might be assumed from Ingoberga's comment of 588-9 that Æthelberht was still not king at that time, but this would not be a safe assumption because Ingoberga might be referring to Æthelberht's status at the time of the marriage.

This implication of Gregory's that Irminric rather than Æthelberht was ruling in about 575 contradicts Bede's statement that Æthelberht reigned for 56 years, which would place the beginning of his reign in 560. However, Bede was writing over a hundred years later, and the two sources can be reconciled if we assume that Bede misinterpreted a statement that Æthelberht lived for 56 years, in which case we could place his date of birth around 560, and his assumption of the throne between his marriage in about 575 and his reception of Augustine in 597. If we assume that Æthelberht was king of Kent at the time of the battle of Wibbandun (likely, but not explicitly stated in the Chronicle), then he was king by 581?588.

The marriage of Æthelberht and Bertha presumably strengthened the already close links between Kent and the Frankish mainland. The marriage also brought Christian influence to Kent, because Bertha was Christian, and brought a bishop called Liudhard with her (Bede, HE, i.24). We do not know whether Liudhard tried to evangelise in the twenty years between his arrival and the arrival of the Roman missionaries in 597, but it is likely that he and Bertha at least worked to make the king more receptive to the Romans when they did arrive.

Bede names Æthelberht as one of the kings who held wide powers in southern England (HE, ii.5). This list must be treated with caution, as Keynes has shown that in places it is more concerned with kings who supported the conversion than with kings who had wide political powers. However, Æthelberht did have some authority beyond the borders of Kent. The Anglo-Saxon Chronicle's reference to a battle at Wibbandun (see entry on 581?588) shows Æthelberht and his army beyond the Kentish borders, and Bede's comments on the conversion of the East Saxons (see entry on 604) note that the East Saxon king Sæberht was Æthelberht's nephew and his subject. Bede also notes that the East Anglian king Rædwald received Christianity in Kent: this might suggest Kentish influence over East Anglia, but probably nothing more definite, since on Rædwald's return home he relapsed into paganism, and Æthelberht neither protested nor established a bishopric there (see entry on c.615-54). For the ecclesiastical meeting on the borders of the West Saxons and the Hwicce, which Bede notes was arranged with Æthelberht's help (HE, ii.2, and see entry on c.602), Æthelberht may only have provided an armed escort. If Æthelberht held the effective control over the East Angles and the West Saxons which Bede suggests at HE, ii.5, we would expect bishoprics to be established in those countries in Æthelberht's reign, rather than a few decades later in the 630s. It seems likely that Æthelberht's direct authority outside of Kent was limited to the East Saxon kingdom, though his influence may well have extended further.

N. Brooks, "The creation and early structure of the kingdom of Kent", The Origins of the Anglo-Saxon Kingdoms (London: 1989), pp.55-74

S. Keynes, "Rædwald the Bretwalda", Voyage to the Other World: The Legacy of Sutton Hoo (Minneapolis: 1992), pp.103-23