880s deaths

Duke of Bohemia (9th century)

Abu-Abdullah Muhammad ibn Īsa Māhānī (, flourished c. 860 and died c. 880) was a Persian mathematician and astronomer born in Mahan, (in today Kermān, Iran) and active in Baghdad, Abbasid Caliphate. His known mathematical works included his commentaries on Euclid's Elements, Archimedes' On the Sphere and Cylinder and Menelaus' Sphaerica, as well as two independent treatises. He unsuccessfully tried to solve a problem posed by Archimedes of cutting a sphere into two volumes of a given ratio, which was later solved by 10th century mathematician Abū Ja'far al-Khāzin. His only known surviving work

Eastern Orthodox hymnographer

9th-century queen of Aquitaine

Danish Viking ruler

poet

Ruler of the Gurjara-Pratihara dynasty

9th-century Al-Andalus Muslim military commander

King of Abkhazia

Duke of Brittany

Chinese chancellor

Muslim jurist and theologian

9th-century Arab leader of the Shayban tribe

9th-century Abbasid senior courtier