1030 (The People's Chronology)
Norway's Olaf II Haraldsson attempts to reconquer his country with help from Anund Jakob (see 1028), but he is defeated on Norwegian soil at the Battle of Stiklestad July 29 and killed at age 35 (approximate) fighting against a superior force of Danish soldiers and Norwegian peasants loyal to Denmark (and England's) king Knut (Canute). Olaf will be canonized next year; his 14-year-old half brother Harald Sigurdsson survives the battle and makes his way to Kiev, where he receives protection from Jaroslav the Wise.
The Holy Roman Emperor Conrad II invades Hungary but is defeated by the forces of Stephen (István) I, who will have some minor conflicts with Bulgaria and Poland but whose long reign will for the most part be peaceful.
The Muslim emirs who have attacked Syria defeat the Byzantine emperor Romanus III in battle.
The Afghan ruler Mahmud of Ghazna dies at Ghazna in late April at age 59, having transformed his capital into a cultural showplace rivaling Baghdad in his 25-year career of pillaging the temples of northern India, capturing slaves, and returning with elephants whose backs were laden with his spoils. He has shared his palace with some 400 poets and is famous for having filled one poet's mouth with pearls three times to show his appreciation for a moving eulogy.
Canon of Medicine by the Arab physician Avicenna (Ibn Sina) follows the thinking of Aristotle and Galen but is so well written and organized that it will be a major influence on medical thinking for centuries.