King Alexander I of Yugoslavia ruled the Kingdom of Serbs, Croats and Slovenes (1921–29) and of Yugoslavia (1929–34).
Alexander the Great was the King of Macedonia. During his leadership he united Greece, reestablished the Corinthian League and conquered the Persian Empire.
Attila the Hun was one of the most successful barbarian rulers of the Hunnic Empire, attacking the Eastern and Western Roman empires.
Hussein bin Talal served as king of Jordan from 1953 to 1999. He helped guide his country into the modern era.
Joseph Bonaparte was the older brother of Napoleon I, who made him king of Spain. He served as Spain's king from 1808 to 1813.
Louis Bonaparte, Napoleon I's third surviving brother, was king of Holland from 1806 to 1810.
Hugh Capet was a 10th century monarch who started the Capetian Dynasty of France.
Charlemagne was the founder of the Carolingian Empire, best known for uniting Western Europe for the first time since the fall of the Roman Empire.
Charles I of Hungary was forced to surrender his power to Wenceslas of Bohemia, but later reclaimed the throne and formed a defensive alliance with Poland.
Charles I was a monarch of the Hapsburg line who was the last emperor of Austria and king of Hungary. He lost his throne at the end of World War I.
Charles II was the monarch of England, Ireland and Scotland during much of the latter half of the 17th century, marking the Restoration era.
Charles IX was King of France from 1560 until 1574 during the turbulent time of the Wars of Religion.
Charles VI, nicknamed Charles the Mad, was king of France from 1380 to 1422—a period marked by political chaos and France’s defeat by England at Agincourt.
King Edward I reigned England from 1272 to 1307, during which time he conquered Wales, expelled the Jews and signed many parliamentary statutes.
King Edward VII took over the British throne after the death of Queen Victoria. He was a popular ruler who strengthened his country prior to World War I.
Edward VIII became king of the United Kingdom following the death of his father, George V, but ruled for less than a year. He abdicated the throne in order to marry his lover, Wallis Simpson, thereafter taking the title Duke of Windsor.
Arab statesman Faisal I was king of Iraq from 1921 to 1933 and a leader in advancing Arab nationalism during and after World War I.
Frederick II, known as Frederick the Great, was Prussia's king from 1740 to 1786. By winning wars and expanding territories, he established Prussia as a strong military power.
Born in 1865, George V served as king of the United Kingdom from 1910 to 1936, during World War I. He was succeeded by his son, George VI, following his death.
George VI served as king of the United Kingdom during World War II and was an important symbolic leader. He was succeeded by Queen Elizabeth II, in 1952.
Henry IV Holy Roman Emperor became king of Germany in 1056 and was abdicated in 1105. He overthrew Pope Gregory VII because of a disagreement about imperial rule.
Henry IV was King of France 1589–1610. The first monarch of France’s Bourbon Dynasty, he issued The Edict of Nantes, granting religious freedom to Protestants.
Henry V served as joint king of Germany with Henry IV until he forced his father to abdicate the throne. Holy Roman emperor from 1111 to 1125, he was the last of the Salian line.
Henry VI was the German king and Holy Roman emperor (1165-1197). His main achievement was increasing his dynasty's power by acquiring of the kingdom of Sicily.
Henry VII was a 13th century German king and son of Frederick II, who was Holy Roman emperor.
Henry VII became the first House of Luxembourg member to serve as king of Germany in 1308. In 1312, he became the House of Luxembourg's first Holy Roman Emperor.
Henry VIII, king of England, was famously married six times and played a critical role in the English Reformation, turning his country into a Protestant nation.
James I was a Spanish king best known for fighting the Moors during his reign from 1213-'76. He is also known as James I the Conqueror and James I of Aragon.
Legendary King Arthur formed the Knights of the Round Table and defended ancient Wales from encroaching Saxons.
King Tut is chiefly known for his intact tomb, discovered in Egypt's Valley of the Kings in 1922. Since then, his remains have held millions in awe over the mystery of his life and death.
Louis VII was king of France who pursued a long rivalry with Henry II of England.
Louis XII was king of France from 1498 and was noted for his disastrous Italian wars and his domestic popularity.
King Louis XIV of France led an absolute monarchy during France’s classical age. He revoked the Edict of Nantes and is known for his aggressive foreign policy.
Louis XV was king of France from 1715 to 1774. He is best known for contributing to the decline of royal authority that led to the French Revolution in 1789.
Louis XVI was the last king of France (1774–92) in the line of Bourbon monarchs preceding the French Revolution of 1789. He was executed for treason by guillotine in 1793.
Macbeth was king of Scotland during the 11th century. He was also the basis for Shakespeare's play Macbeth.
Mahmud of Ghazna is best known as the the leader of the Ghaznavid dynasty in modern-day Iran, Afghanistan, Pakistan and northwest India.
Maximilian I was the first king of Bavaria (1806–25), a member of the house of Wittelsbach.
Miguel I was became regent of Portugal in February 1828, and ruled the nation as a self-proclaimed king from 1828 to 1834, though his royal title wasn't recognized everywhere.
King Philip II of Spain, also known as Philip the Prudent, ruled one of the world's largest empires. The Philippines are named after him.
Richard III was king of England for two turbulent years. He is best known for being accused of murdering his nephews to protect his throne.
Robert II was king of Scotland from 1371 to 1390, and is best known for his largely ineffectual reign.
Saul was best known as the first King of Israel circa 1046 BC.
King Mohammed Zahir Shah was king of Afghanistan from 1933 to 1973, during which time he provided an era of stable government to his country.
Stephen of Blois was king of England from 1135 to 1141. His reign was marked by a civil war known as The Anarchy.
Pharaoh Thutmose III was the warrior king of Egypt’s 18th and largest dynasty. During his reign, he reestablished Egyptian rule of Syria and Palestine.
William I is best known for ruling Prussia as regent, and king, and later as German emperor.