The Rus' first raid Constantinople
A Rus' fleet suddenly appears before the Byzantine capital

Some 200 Rus' boats ravaged the outskirts of Constantinople while the emperor was away with the army. Patriarch Photios described the citizens' terror in his sermons. It is the first reliable appearance of the Rus' in Byzantine sources, two years before the chronicle's 'calling of the Varangians'.
Wikipedia (Russian) · Wikipedia (English) · 9th century
Meanwhile around the world (±25 years)
Europe
- 843 Treaty of Verdun — 17 years earlier
Africa
- 859 Fatima al-Fihri founds al-Qarawiyyin — 1 year earlier
Asia
- 868 The Diamond Sutra is printed — 8 years later
Alive at the time
- Charles the Bald (aged 37)
- Rurik (aged 30)
- Oleg the Wise (aged 15)
- Alfred the Great (aged 11)