June 15 in History

Assyria was a major ancient Mesopotamian civilization that existed as a city-state from the 21st century BC to the 14th century BC and eventually expanded into an empire from the 14th century BC to the 7th century BC. Assyrian history spans from the early Bronze Age to the late Iron Age; modern historians typically divide ancient Assyrian history into the Early Assyrian, Old Assyrian, Middle Assyrian, Neo-Assyrian, and post-imperial periods, based on political events and gradual changes in language. Assur, the first Assyrian capital, was founded c. 2600 BC, but there is no evidence that the city was independent until the collapse of the Third Dynasty of Ur, in the 21st century BC, when a line of independent kings starting with Puzur-Ashur I began ruling the city. Centered in the Assyrian heartland in northern Mesopotamia, Assyrian power fluctuated over time. The city underwent several periods of foreign rule or domination before Assyria rose under Ashur-uballit I in the early 14th century BC as the Middle Assyrian Empire. In the Middle and Neo-Assyrian periods, Assyria was one of the two major Mesopotamian kingdoms, alongside Babylonia in the south, and at times became the dominant power in the ancient Near East. Assyria was at its strongest in the Neo-Assyrian period, when the Assyrian army was the strongest military power in the world and the Assyrians ruled the largest empire then yet assembled in world history, spanning from parts of modern-day Iran in the east to Egypt in the west.

The Battle of Soissons was fought on 15 June 923 between an alliance of Frankish insurgent nobles led by Robert I, elected king in an assembly the year prior, and an army composed of Lotharingians, Normans, and Carolingian forces under King Charles III's command. The battle took place at Soissons, near Aisne. Robert was killed, but his army won the war. Charles was imprisoned by Herbert II of Vermandois and held captive until his death in 929. Rudolph, Duke of Burgundy, Robert's son-in-law, succeeded him as ruler of West Francia.

John was King of England from 1199 until his death in 1216. He lost the Duchy of Normandy and most of his other French lands to King Philip II of France, resulting in the collapse of the Angevin Empire and contributing to the subsequent growth in power of the French Capetian dynasty during the 13th century. The baronial revolt at the end of John's reign led to the sealing of Magna Carta, a document considered a foundational milestone in English and later British constitutional history.

Frederick II, known as Frederick the Quarrelsome, was Duke of Austria and Styria from 1230 until his death. He was the fifth and last Austrian duke from the House of Babenberg, since the former margraviate was elevated to a duchy by the 1156 Privilegium Minus. He was killed in the Battle of the Leitha River, leaving no male heirs.

The Tiepolo conspiracy or Tiepolo-Querini conspiracy was an attempt to overthrow the government of the Republic of Venice under Doge Pietro Gradenigo. Headed by the disaffected patricians Bajamonte Tiepolo, Marco Querini, and Badoero Badoer but backed by a sizeable number of other patricians, churchmen, and commoners, the conspiracy resulted in a coup attempt on 15 June 1310, in which three columns, each led by one of the chief conspirators, were meant to converge on the Piazza San Marco, seize the Doge's Palace, and overthrow the Venetian government. Warned of the plot at the last minute, the Doge mobilized his followers and loyalist forces. Coupled with the conspirators' poor coordination, the Doge's decisive counter-action led to the coup's failure. Querini, the main driving force of the conspiracy, was killed in the subsequent fighting along with one of his sons. Badoer was captured while trying to cross the Venetian Lagoon from Padua and executed for treason. Tiepolo was pushed back and barricaded in the Rialto. The Great Council let Tiepolo and his main supporters leave in exile.