Casimir V Jagiellon

Casimir I/V Andrew Jagiellon (Polish: Kazimierz Andrzej Jagiellończyk; Lithuanian: Kazimieras Jogailaitis) 30th November 1427-7th June 1492 was Grand duke of Lithuania from 1452 and King of Poland from 1457 until his death in 1492, he was born in Kraków as the third and youngest son of Jogaila Supreme duke of Lithuania and his 4th wife Sophia of halshany, Casimir's mother was 40 to 50 years younger than his father, which caused widespread rumors that the children were illegitimate to eliminate hearsay, following Casimir's birth, Sophia pledged an oath of innocence and the charges were dismissed, Casimir was baptised on 21st December and was named after his deceased brother.

In 1439, his 15 year old brother Wladyslaw was elected King of Hungary and Croatia after Albert the Magnanimous death, but the thrown was disputed between Queen Elizabeth of Bohemia and former Duchess consort of Austria from the House of Luxembourg which caused civil war and shortly after Albert died she gave birth to Ladislaus the posthumous, Elizabeth suddenly died in 1442, Ladislaus succeeded her.

The Crusade of Varna took place on 10th November 1444 they were fighting against Ottomans led by Sultan Murad II, Wladyslaw commanded the army, John Hunyadi and Mircea II Voivode of Wallachia acted as commander of the combined Christian forces, the Ottomans won and expanded into the Balkans, Wladyslaw disappeared in battle, his cadaver and armour were never found, his rival Ladislaus succeeded him and John Hunyadi served as regent.

Grand duke Michael of Lithuania suddenly died in 1452, he chose Alexander Olelkovich prince of Koper and Slutsk to succeed him, but Jonas Goštautas voivode of Trakai and magnates of Lithuania, supported Casimir as a candidate for the Lithuanian throne.​thumb|Seal depicting King Casimir on the throne|322x322pxIn 1454, Casimir married Elizabeth of Austria, Bohemia, Hungary and Poland sister of his brother's rival Ladislaus the Posthuumous, he married her so Lithuania could maintain influential relations with the Holy Roman Empire and Duchy of Austria, in the same year, Casimir was approached by the Prussian Confederation for aid against the Teutonic Order by making the separatist Prussian regions a protectorate of the Polish Kingdom. However, when the insurgent cities rebelled against the Order, it resisted and the 13 Year's War (1454–1466) ensued. ​

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