Al-Bukhari compiles his Sahih
A scholar from Bukhara sifts hadith for sixteen years

Muhammad al-Bukhari travelled through the Hijaz, Iraq, Syria and Egypt collecting reports of the Prophet Muhammad's words and deeds. Tradition says he chose about 7,000 of 600,000 hadith; for Sunni Muslims his Sahih is the most trusted book after the Quran.
Wikipedia (Russian) · Wikipedia (English) · 9th century
Meanwhile around the world (±25 years)
Europe
- 843 Treaty of Verdun — 3 years earlier
- 865 Great Heathen Army — 19 years later
Eastern Europe & Russia
- c. 862 Calling of the Varangians — 16 years later
Africa
- 859 Fatima al-Fihri founds al-Qarawiyyin — 13 years later
Alive at the time
- Al-Khwarizmi (aged 66)
- Charles the Bald (aged 23)
- Rurik (aged 16)
- Oleg the Wise (aged 1)
- Al-Kindi (aged 45)