There are many indications of close relations between Kent and the Franks. Æthelberht's marriage to Bertha certainly connected the two courts, although not as equals: the Franks would have thought of Æthelberht as an under-king. There is no record that Æthelberht ever accepted a continental king as his overlord and, as a result, historians are divided on the true nature of the relationship. Evidence for an explicit Frankish overlordship of Kent comes from a letter written by Pope Gregory the Great to Theuderic, king of Burgundy, and Theudebert, king of Austrasia. The letter concerned Augustine's mission to Kent in 597, and in it Gregory says that he believes "that you wish your subjects in every respect to be converted to that faith in which you, their kings and lords, stand". It may be that this is a papal compliment, rather than a description of the relationship between the kingdoms. It also has been suggested that Liudhard, Bertha's chaplain, was intended as a representative of the Frankish church in Kent, which also could be interpreted as evidence of overlordship.