April 13

Born Lý Bôn in 503 in what is now northern Vietnam. He served as a local magistrate under Chinese rule before leading a successful uprising in 541. In 542, he proclaimed himself emperor of the newly formed kingdom of Vạn Xuân. As emperor, he organized a centralized administration and appointed trusted officials. He defended his realm against multiple incursions by the Liang dynasty. He died in 548 after years of struggle to maintain Vietnam's autonomy.

He was the eldest son of King Liuvigild of the Visigothic Kingdom. Originally raised in the Arian Christian tradition of his father, he embraced Catholicism in 579. His conversion created a rift with his father, leading to a rebellion in Seville. After a two-year revolt, he was captured and imprisoned by royal forces. He died in 585, reputedly executed for refusing to renounce his Catholic faith. He was later canonized and venerated as a martyr within the Catholic Church.

Born around 720, likely in Lucca of Lombard descent. He joined the Benedictine monastery of Monte Cassino and took the name Paulus Diaconus. From around 760, he served at the court of King Desiderius of the Lombards. He authored major works including the Historia Langobardorum, chronicling the history of his people. His writings also include hagiographies and hymns that influenced medieval scholarship. He died around 799, leaving a lasting legacy as a key source for early medieval history.

Reigning from 803 to 814, Krum expanded Bulgarian territory through successful campaigns against the Byzantine Empire. He famously crushed a Byzantine army at the Battle of Pliska in 811, reputedly killing Emperor Nikephoros I. Krum is credited with establishing one of the earliest Bulgar legal codes to strengthen central authority. He fortified cities and implemented measures to organize and tax conquered lands. His reign laid the foundations for the later golden age of the Bulgarian Empire. He died in 814 during preparations for another campaign against Byzantium.

Born around 812, Donald I was a member of the royal house that united the Picts and Scots. He ascended the throne after the death of his brother Kenneth I in 859. His brief reign focused on consolidating power in present-day Scotland amid ongoing regional conflicts. He is thought to have ruled from the royal center at Scone, maintaining Pictish traditions. Donald I died in 862 and was succeeded by his nephew, Constantine I. Although little is recorded of his achievements, he helped to stabilize the early Scottish kingdom.

A member of the distinguished Phokas family, Bardas served as a commander in the late 10th century. He led several successful expeditions against Muslim emirates in Asia Minor, reinforcing Byzantine frontiers. He was praised for his tactical skill and courage in battle, earning the respect of Emperor Basil II. His victories helped to secure key mountain passes and weaken Arab control in Anatolia. Despite his achievements, he died in 989 before he could attain the highest military offices. His legacy continued through his descendants, who played a major role in Byzantine politics.

Herbert I inherited the county of Maine in northern France during a period of feudal fragmentation. He maintained alliances and engaged in skirmishes to protect his realm from encroachment by the Dukes of Normandy. Through strategic marriages and military actions, he preserved a degree of autonomy for Maine. His rule saw the construction and reinforcement of key castles to guard against external threats. Herbert's tenure helped to shape the political map of northwestern France in the early medieval period. He died in 1035, leaving Maine contested by powerful neighbors.

Born in 1030, Vsevolod was the son of Yaroslav the Wise and a member of the Rurik dynasty. He initially ruled Pereyaslavl before ascending to the Kievan throne after internal strife among his brothers. His reign was marked by efforts to uphold the legal reforms of his father and to strengthen central authority. Vsevolod balanced relations with nomadic tribes such as the Kipchaks through diplomacy and military action. He patronized churches and promoted the spread of Christianity throughout his realms. He died in 1093, after which Kievan Rus experienced renewed conflicts among his successors.

Daughter of Godfrey III, Duke of Lower Lorraine, Ida was born around 1040 into a prominent noble family. She married Eustace II, Count of Boulogne, and later became a widow with a strong religious calling. Ida retired to a monastic life, supporting the foundation of convents and caring for the poor. Her dedication to charity and spiritual devotion earned her canonization as a saint after her death in 1113. As abbess of the convent at Boulogne, she guided religious women in the Rule of Saint Benedict. Her feast day is observed by various Christian communities in recognition of her faith and service.

Born in 1076, Simon succeeded his father Thierry II as Duke of Lorraine in 1115. He opposed Emperor Henry V's attempts to exert imperial control over his duchy. Through legal and military means, Simon defended Lorraine's autonomy within the Holy Roman Empire. He founded monasteries and supported ecclesiastical reform movements in his territories. Simon's reign was marked by feuds with local bishops and counts who challenged ducal prerogatives. He died in 1138, leaving a strengthened ducal office for his successors.

Guy of Thouars was a French nobleman who became the third husband of Constance, Duchess of Brittany. After her death, he governed Brittany as regent for their young daughters, Alix and Catherine. His rule involved navigating feudal struggles with the Plantagenets and Breton nobility. He worked to preserve the duchy's autonomy amidst external pressures. His regency established the path for his daughters' succession. He died in 1213, leaving a complex legacy in Brittany's medieval history.

Eleanor of England was born in 1215 as the youngest daughter of King John of England and Isabella of Angoulême. She married Simon de Montfort, 6th Earl of Leicester, a key figure in the baronial opposition to King Henry III. As Countess of Leicester, she accompanied her husband in political affairs and spent periods managing their estates. Following the defeat and death of Simon de Montfort at the Battle of Evesham, Eleanor returned to England. She lived quietly thereafter, preserving her memory as a royal princess involved in one of the most tumultuous rebellions against the crown. Eleanor died in 1275, leaving a legacy intertwined with the early development of English parliamentary governance.