5 events the sources record for this year, grouped by region.
What happened
China (1)
Xia returned 149 officers and soldiers lost at Yongle; in exchange, it was agreed to return Mizhi, Jialu, Futu and Anjiang four villages and send officials to demarcate the border. (Xu Zizhi Tongjian (Continuation of the Comprehensive Mirror) 續資治通鑑 卷081 (1090년 조))
Japan (1)
The retired emperor visited Kumano. (Fusō Ryakuki part_02 줄 441)
Southern Europe (2)
To counter Tzachas, the emperor sent troops by sea to fortify Methymna. (Anna Komnene, The Alexiad Dawes 7.8 (문장 8))
The Scythians surrounded the city, and the emperor was in effect besieged from within. (Anna Komnene, The Alexiad Dawes 7.11 (문장 4))
Western Europe (1)
William, to attack his elder brother Robert, took the castle and port of Saint-Valery and Aumale. (Anglo-Saxon Chronicle Giles/Ingram 1847 A.D. 1090 항 (pg657.txt 줄 7886))