June 18

Born in 685, Leo III the Isaurian seized the throne after a successful revolt against Emperor Anastasius II. He famously repelled the Second Arab Siege of Constantinople in 717–718, securing the empire's survival. He implemented the Iconoclasm movement, banning religious images and sparking controversy with the Byzantine Church and the Papacy. His legal codifications and fiscal reforms strengthened the imperial administration. His reign marked a turning point in Byzantine military and religious history.

Little is known about Zhang Hao's early life, but he emerged as a leading military commander under the warlord Yang Xingmi. In the volatile politics following Yang Xingmi’s death, he conspired with fellow general Xu Wen in the assassination of Yang Wo in 908. Soon after, internal power struggles turned violent, and Zhang Hao was himself assassinated by Xu Wen, who went on to dominate the Wu regime. Zhang Hao's brief career reflects the era’s factional conflicts and shifting loyalties in southern China.

Born around 1050 as the daughter of King Andrew I of Hungary, Sophia married Vratislaus II, Duke (later King) of Bohemia. As duchess, she acted as a mediator between Hungarian and Bohemian courts and played a role in arranging alliances. After Vratislaus was crowned the first King of Bohemia in 1085, Sophia held the title of queen consort. Widowed in 1092, she retired to the Benedictine monastery of Třebnice and devoted her later years to religious life. She died in 1095, remembered for her piety and diplomatic acumen.

Elisabeth of Schönau was born around 1129 and entered the Benedictine Abbey of Schönau in the Rhineland at an early age. She became renowned for receiving mystical visions and prophecies concerning the Church and secular rulers. Her detailed visionary accounts were recorded by her brother and fellow monk, Ebbo of Schönau. She corresponded with popes and bishops, offering spiritual guidance and prophecy during times of crisis. Elisabeth’s writings had a lasting impact on medieval spirituality and visionary literature.

Born in 1218, Chūkyō ascended the Chrysanthemum Throne in 1221 during the Jōkyū War between the imperial court and the Kamakura shogunate. His accession was part of cloistered Emperor Go-Toba's efforts to assert authority, but the shogunate swiftly quashed the rebellion. Chūkyō was deposed after a few months and replaced by Emperor Go-Horikawa, spending the remainder of his life in relative obscurity. He died in 1234 at the age of 16. His short-lived reign highlights the power struggle between imperial and samurai authorities in early medieval Japan.

Born around 1181 as the daughter of King Sancho I of Portugal, Theresa married King Alfonso IX of León in 1191. As queen consort, she played an active role in court politics and patronized monasteries. After Alfonso's death in 1230, she served as regent for their son, Ferdinand III of Castile and León, helping to stabilize the kingdom. Known for her diplomatic skill, Theresa negotiated treaties with neighboring realms and supported the Reconquista efforts. She died in 1250, leaving a legacy as a strong female ruler in medieval Iberia.

Born in 1265, Alfonso III succeeded his father, Peter III, as King of Aragon and Count of Barcelona in 1285. He secured the Kingdom of Valencia and completed the conquest of the Balearic Islands, strengthening Aragonese maritime power. He also reclaimed Sicily from Angevin control, later ceding it in political negotiations. His reign saw legal reforms and urban development across his territories. Alfonso died unexpectedly in 1291 at the age of 26, leaving a consolidated realm to his successors.

Henry XV was born in 1312 as the son of Duke Henry XIV of Lower Bavaria and Margarete of Bohemia. He inherited the ducal title as a minor in 1330, with his uncle and cousins acting as regents. His short reign saw little direct governance, as regents managed the duchy’s affairs. Henry died unmarried and without issue in 1333 at the age of 21, leading to the partition of Lower Bavaria among rival branches of the Wittelsbach dynasty. His life reflects the complexities of dynastic succession in medieval Germany.

Born around 1400 in Tournai, Rogier van der Weyden moved to Brussels where he became the city’s official painter. His works, such as the Descent from the Cross, are renowned for their dramatic intensity and masterful use of color and composition. He influenced a generation of Northern European artists with his realistic detail and emotional depth. Van der Weyden’s portraits and devotional paintings were highly sought after by European courts and the Church. He died in 1464, leaving a legacy as one of the most important painters of the 15th century.

Born in 1517, Robert Crowley was an influential figure in the English Reformation, working as a printer and bookseller in London. He published vernacular translations of the Bible and religious tracts, promoting Protestant ideas. Crowley also wrote poetry and satirical verses critiquing social injustices. During the reign of Mary I, he went into exile in Frankfurt, returning to England under Elizabeth I to serve as rector of Tunstall. He died in 1588, remembered for his prolific writings and support for religious reform.

Piet Pieterszoon Hein (1577–1629) was a Dutch naval officer during the Eighty Years' War and the Dutch–Portuguese War. He rose to prominence as a privateer and admiral in the Dutch West India Company. In 1628, he achieved a spectacular victory by capturing the Spanish treasure fleet, securing vast riches for the Dutch Republic. This feat boosted morale and funding for the Dutch war efforts and made him a national hero. Hein's daring actions and leadership have made him one of the most celebrated figures in Dutch naval history. He died the following year during a naval engagement in the Caribbean.

Christoph Scheiner (1575–1650) was a German Jesuit priest and pioneering astronomer. He made some of the earliest telescopic observations of sunspots and their movement across the solar disk. Scheiner invented the helioscope to project sunlight safely for solar observation. He engaged in a famous priority dispute with Galileo Galilei over the discovery of sunspots. His work in optics and astronomy contributed significantly to the understanding of solar phenomena. Later in life, he served as a professor of mathematics and philosophy for the Jesuit order. He left a lasting legacy as a key figure in early 17th-century astronomy.