6 events the sources record for this year, grouped by region.
What happened
Japan (5)
In the seventh month, on day 庚戌, prayers are offered in advance to the Ise Grand Shrine to stop the wind and rain; the same day a storm blows houses away and floods overflow. (Nihon Montoku Tennō Jitsuroku 日本文德天皇實錄 卷第六 「齊衡元年」 7月)
In the fourth month, on day 壬午, Mutsu province reports signs of unrest (poor harvest, soldiers deserting, bandit gangs like tigers) and asks for 1,000 reinforcements; granted. (Nihon Montoku Tennō Jitsuroku 日本文德天皇實錄 卷第六 「齊衡元年」 4月)
In the fifth month, on day 戊戌, 10,000 koku of grain is given to Mutsu province to relieve the captured barbarians (fushū). (Nihon Montoku Tennō Jitsuroku 日本文德天皇實錄 卷第六 「齊衡元年」 5月)
In the seventh month, on day 乙巳, Bizen province presents an upasaka (lay devotee) who has refused grain; he is placed at Shinten-in, people gather, and they call him a saint. (Nihon Montoku Tennō Jitsuroku 日本文德天皇實錄 卷第六 「齊衡元年」 7月)
On the last day of the eleventh month (辛亥), Iwami province presents a sweet spring (reisen); an edict changes the fourth year of Ninju to Saikō. (Nihon Montoku Tennō Jitsuroku 日本文德天皇實錄 卷第六 「齊衡元年」 11月)
Southern Europe (1)
King Æthelwulf went to Rome with great pomp and stayed there a year; on the way back he took Judith, daughter of the Frankish king Charles, as his queen. (Anglo-Saxon Chronicle Giles/Ingram 1847 A.D. 854 항 (pg657.txt 줄 2655))