Because of epidemic illness many died; the bones in the capital were gathered and buried, the Daihannya sutra was read at the great temples and in the Kinai and the seven circuits, and rice and salt were given to the sick. (Nihon Kōki (Later Chronicles of Japan) 日本後紀 卷16)
Because of epidemic disease, horse archery was halted. Owing to flood damage in the first year of Daidō and the many who fell ill in epidemics since the year before, unpaid official grain (shōzei) was remitted for households with seven-tenths or more damage. (Nihon Kōki (Later Chronicles of Japan) 日本後紀 卷17)
When Danish King Godofrid invades Abodritia with an army, the emperor sends his son Charles with Frankish and Saxon troops to the Elbe. Godofrid camps on the coast for several days, takes several Slav castles and withdraws with heavy losses; he drives out Duke Trasco and deceives and captures Godelaibus, hanging him. Charles builds a bridge over the Elbe, crosses with the army, plunders the lands of the Linones and Smeldingi, and returns (Royal Frankish Annals ARF a.808, Kurze 1895 p.125)
Before going home, Godofrid destroys the trading port of Reric on the ocean coast and moves the merchants away (Royal Frankish Annals ARF a.808, Kurze 1895 p.126)
Godofrid disbands his fleet and comes to the port of Sliesthorp, where he stays several days; he decides to block the border facing Saxony with a rampart along the north bank of the Eider River (Royal Frankish Annals ARF a.808, Kurze 1895 p.126)