Perpetual peace is celebrated between the Lombard King Agilulf and the Avar Khagan as Byzantine Istria is attacked by the combined forces of the Lombards, Avars, and Slavs (narrative account from Paul the Deacon's History of the Lombards).
Hac tempestate legati Agilulfi regressi a cacano pacem perpetuam factam cum Avaribus nuntiarunt. Legatus quoque cacani cum eis adveniens, ad Gallias perrexit, denuntians Francorum regibus, ut, sicut cum Avaribus, ita pacem habeant cum Langobardis.
Inter hec Langobardi cum Avaribus et Sclavis Histrorum fines ingressi, universa ignibus et rapinis vastavere.
At this time the ambassadors of Agilulf who returned from the Khagan announced a perpetual peace concluded with the Avars. Also, an ambassador of the Khagan came with them and proceeded to Gaul, demanding from the kings of the Franks that they should have peace with the Lombards the same way as they had with the Avars.
Meanwhile the Lombards invaded the territories of the Istrians with the Avars and the Slavs, and laid waste to everything with burnings and plundering.
[translation taken from Paul the Deacon, History of the Lombards, trans. William Dudley Foulke, ed. Edward Peters (Philadelphia 2003; 1st ed. 1907), p. 167, and slightly modified by the editor.]
The account refers to the counter-offensive launched by the Lombard-Avar-Slavic in the wake of the Byzantine victory over the Slavs in 599 which Pope Gregory I mentioned in one of his letters to the triumphant exarch of Ravenna (see the source here). The episode is a part of the story arc that includes the following sources:
1) The letter of Pope Gregory I to Callinicus, the Exarch of Ravenna, dated May of 599, mentioning the victory over the Slavs in a battle fought, most probably, in Istria (see the source here);
2) The letter of Pope Gregory I to Maximus, the Bishop of Salona, mentioning the Slavic incursions into Italy by way of Istria (see the source here);
3) The narrative accounts of 7th-century Slavic incursions penned by John the Deacon (see the source here);
4) The narrative accounts of Slavic incursions penned by Paul the Deacon (the source hereby edited);
5) The narrative account from Liber pontificalis regarding the mission of abbot Martin, sent by Pope John IV to retrieve the relics from Dalmatia and Istria (see the source here).
After the middle of the 7th century, there are no more written testimonies of Slavic presence in Istria until the fateful Plea of Rižana of 804 (see the source here).
The images come from the project I libri dei patriarchi, available freely online on the following link: https://www.librideipatriarchi.it/
The editor has subsequently marked the images with a red vertical arrows simply to denote the parts of the manuscript that are hereby edited.
All images remain under the copyright of their respective institutions.