Died in 1440

Feb 14 Dietrich Count of Oldenburg a feudal lord in Northern Germany, holding the counties of Delmenhorst and Oldenburg. He was called "Fortunatus" as he was able to secure Delmenhorst for his branch of the Oldenburgs
Mar 9 Frances of Rome an Italian saint who was a wife, mother, mystic, organizer of charitable services and a Benedictine oblate who founded a religious community of oblates, who share a common life without religious vows.
Mar 20 Sigismund Kęstutaitis the Grand Duke of Lithuania from 1432 to 1440. Sigismund was his baptismal name; Sigismund's pagan Lithuanian birth name is unknown. He was the son of the Grand Duke of Lithuania Kęstutis and his wife Birutė
May 7 Frederick IV Landgrave of Thuringia a member of the House of Wettin and was Margrave of Meissen and Landgrave of Thuringia.
Sep 20 Frederick I Elector of Brandenburg Burgrave of Nuremberg as Frederick VI and Elector of Brandenburg as Frederick He was a son of Burgrave Frederick V of Nuremberg and Elisabeth of Meissen, and was the first member of the House of Hohenzollern to rule the Margraviate of Brandenburg.
Sep 23 Lorenzo the Elder an Italian banker of the House of Medici of Florence, the younger brother of Cosimo de' Medici the Elder and the founder of the so-called dei Popolani line of the family.
Sep 30 Reginald Grey 3rd Baron Grey de Ruthyn a powerful Welsh marcher lord, succeeded to the title on his father Reginald's death in July 1388.
Oct 26 Gilles de Rais a knight and lord from Brittany, Anjou and Poitou, a leader in the French army, and a companion-in-arms of Joan of Arc. He is best known for his reputation and later conviction as a presumed serial killer of children
Nov 24 William Douglas 6th Earl of Douglas a short-lived Scottish nobleman. He was Earl of Douglas and Wigtown, Lord of Galloway, Lord of Bothwell, Selkirk and Ettrick Forest, Eskdale, Lauderdale, and Annandale in Scotland, and de jure Duke of Touraine, Count of Longueville, and Lord of Dun-le-roi in France. He was the eldest son of Archibald Douglas, 5th Earl of Douglas and Eupheme Graham