AD 69day.year

The Roman Senate declares Vespasian emperor of Rome, the last in the Year of the Four Emperors.

The Roman Senate proclaims Vespasian as emperor in AD 69, concluding the Year of the Four Emperors and ushering in the Flavian dynasty.
In AD 69, Rome experienced a year of political chaos known as the Year of the Four Emperors. After the deaths of Galba, Otho, and Vitellius, the Senate turned to Vespasian. On December 21, Vespasian was formally declared emperor by the Senate. His rise marked the end of rapid imperial turnover and the start of the Flavian dynasty. Under Vespasian, Rome saw relative stability and significant building projects. This event laid the groundwork for decades of Flavian rule.
AD 69 Roman Senate Vespasian emperor of Rome Year of the Four Emperors
1124day.year

Pope Honorius II is consecrated, having been elected after the controversial dethroning of Pope Celestine II.

Pope Honorius II is consecrated in 1124, following the contentious removal of Pope Celestine II.
The papal election of 1124 was marked by intense factional disputes within the College of Cardinals. After Pope Celestine II was deposed, Lamberto Scannabecchi secured enough support to become Honorius II. His consecration on December 21 solidified his position amid accusations of political maneuvering. Honorius II would later navigate conflicts between the papacy, the Holy Roman Emperor, and the Norman kingdom of Sicily. His reign saw important church reforms and the continuance of Gregorian policies. This moment reflects the close intertwining of religion and politics in medieval Europe.
1124 Pope Honorius II
1140day.year

After a siege of several weeks, the city of Weinsberg and its castle surrender to Conrad III of Germany.

After a weeks-long siege, the city of Weinsberg surrenders to Conrad III of Germany in 1140.
In 1140, King Conrad III mounted a campaign to assert his authority in southern Germany. The fortified city of Weinsberg, held by his rivals, resisted a lengthy siege. On December 21, weakened by starvation and constant assault, the defenders yielded to Conrad’s forces. This victory secured Conrad’s influence in the region and discouraged further rebellions. The fall of Weinsberg highlights the brutal realities of medieval warfare and dynastic power struggles. It also demonstrated the strategic importance of fortified cities in the Holy Roman Empire.
1140 siege of several weeks Conrad III of Germany
1237day.year

The city of Ryazan is sacked by the Mongol army of Batu Khan.

Batu Khan’s Mongol army sacks the Russian city of Ryazan in 1237, marking the start of the Mongol invasion of Rus'.
In December 1237, Batu Khan led Mongol forces into the Russian principalities. Ryazan was among the first cities to face the Mongol onslaught and strong fortifications. After a fierce assault, the defenders were overwhelmed and the city was razed on December 21. The fall of Ryazan sent shockwaves through Rus’, leading to further conquests of other principalities. This brutal campaign reshaped Eastern European politics and opened the region to Mongol dominance. The event stands as a testament to the Mongols’ military prowess and the vulnerability of fragmented states.
1237 Ryazan sacked Mongol Batu Khan
1361day.year

The Battle of Linuesa is fought in the context of the Spanish Reconquista between the forces of the Emirate of Granada and the combined army of the Kingdom of Castile and of Jaén resulting in a Castilian victory.

The Battle of Linuesa in 1361 sees Castilian forces defeat the Emirate of Granada during the Reconquista.
In the winter of 1361, Castilian troops clashed with the forces of the Emirate of Granada near the Liñosa River. Under King Peter I of Castile, the Christian army sought to push further into Muslim-held territory. On December 21, the Castilians secured a decisive victory, routing the Granadan forces. This triumph boosted morale in Castile and weakened Granada’s defensive capacity. The battle is one of many during the centuries-long Reconquista, which aimed to reclaim Iberia from Muslim rule. It exemplifies the shifting frontiers and intermittent warfare that defined medieval Spain.
1361 Battle of Linuesa Reconquista Emirate of Granada Kingdom of Castile Jaén
1598day.year

Battle of Curalaba: The revolting Mapuche, led by cacique Pelentaru, inflict a major defeat on Spanish troops in southern Chile.

The Mapuche, led by Pelentaru, deal a major defeat to Spanish troops at the Battle of Curalaba in 1598.
In 1598, the indigenous Mapuche people revolted against Spanish colonial rule in southern Chile. Under the leadership of cacique Pelentaru, they ambushed a Spanish column near Curalaba. On December 21, the Mapuche annihilated the expedition, killing the governor and most of his men. This victory triggered the Great Mapuche Uprising, pushing the Spanish south of the Bío-Bío River. The battle marked a turning point, ending Spain’s early advances and securing Mapuche autonomy in the south. It remains a symbol of indigenous resistance in Latin American history.
1598 Battle of Curalaba Mapuche cacique Pelentaru Spanish Chile
1620day.year

Plymouth Colony: William Bradford and the Mayflower Pilgrims land near what is now known as Plymouth Rock in Plymouth, Massachusetts.

William Bradford and the Mayflower Pilgrims land at Plymouth Rock, establishing Plymouth Colony in 1620.
In November 1620, a group of English Puritans set sail aboard the Mayflower seeking religious freedom. After a treacherous Atlantic crossing, they spotted land near Cape Cod in December. On December 21, William Bradford and the Pilgrims made camp at what became Plymouth Rock. They soon drafted the Mayflower Compact, establishing a self-governing community. Plymouth Colony became one of the earliest successful English settlements in North America. Their perseverance and cooperative spirit would shape colonial society and American identity.
1620 Plymouth Colony William Bradford Mayflower Pilgrims Plymouth Rock Plymouth, Massachusetts
1826day.year

American settlers in Nacogdoches, Mexican Texas, declare their independence, starting the Fredonian Rebellion.

American settlers in Nacogdoches declare independence, igniting the Fredonian Rebellion in Mexican Texas, 1826.
In late 1826, tensions rose between Mexican authorities and Anglo-American settlers in Texas. Haden Edwards and other settlers in Nacogdoches claimed an expired land grant as nullified. On December 21, they proclaimed the Republic of Fredonia, declaring independence from Mexico. The Fredonian Rebellion was short-lived, collapsing within weeks under Mexican pressure and local opposition. Though it failed, the uprising foreshadowed future conflicts that led to Texas’s independence. The event underscores early Texan resistance to Mexican rule and settler-Mexican relations.
1826 Nacogdoches Mexican Texas Fredonian Rebellion
1832day.year

Egyptian–Ottoman War: Egyptian forces decisively defeat Ottoman troops at the Battle of Konya.

Egyptian forces under Ibrahim Pasha defeat the Ottomans at the Battle of Konya in 1832.
During the Egyptian–Ottoman War, Muhammad Ali’s modernized army advanced into Anatolia. Led by Ibrahim Pasha, Egyptian troops confronted Ottoman forces near Konya. On December 21, 1832, the Egyptians delivered a crushing defeat to the Sultan’s army. This victory forced the Ottomans to sue for peace and ceded territory in Syria and Arabia. European powers soon intervened to restrain Muhammad Ali’s ambitions in the Eastern Question. The battle highlighted the effectiveness of military reforms in early 19th-century Egypt.
1832 Egyptian–Ottoman War Egyptian Ottoman Battle of Konya
1844day.year

The Rochdale Society of Equitable Pioneers commences business at its cooperative in Rochdale, England, starting the Cooperative movement.

The Rochdale Society of Equitable Pioneers opens its cooperative shop, launching the modern cooperative movement in 1844.
In Rochdale, England, a group of 28 weavers and workers sought fair pricing and quality goods. On December 21, 1844, they established their cooperative store based on democratic principles. Their ‘Rochdale Principles’ included open membership, limited interest, and education. The model emphasized profit sharing and community welfare, setting a template for cooperatives. News of their success spread rapidly, inspiring consumer and producer cooperatives worldwide. Today, the Rochdale Society is celebrated as the foundation of the global cooperative movement.
1844 Rochdale Society of Equitable Pioneers cooperative Rochdale starting the Cooperative movement
1861day.year

Medal of Honor: Public Resolution 82, containing a provision for a Navy Medal of Valor, is signed into law by President Abraham Lincoln.

President Abraham Lincoln signs Public Resolution 82, establishing a Navy Medal of Valor alongside the Army Medal of Honor.
On December 21, 1861, U.S. President Abraham Lincoln enacted Public Resolution 82 in response to calls for recognizing naval heroism. This resolution authorized the creation of a Navy Medal of Valor alongside the existing Army Medal of Honor. Although initially overshadowed by its army counterpart, the naval decoration laid the groundwork for future naval honors. The law marked the first statutory recognition of extraordinary bravery by sailors during the American Civil War. Over time, the Navy Medal of Valor would be integrated into the modern Medal of Honor system. Lincoln's decision underscored the importance of valor and sacrifice in the young nation's armed forces.
1861 Medal of Honor President Abraham Lincoln
1872day.year

Challenger expedition: HMS Challenger, commanded by Captain George Nares, sails from Portsmouth, England.

HMS Challenger departs Portsmouth on a pioneering scientific voyage, launching the Challenger expedition that founded modern oceanography.
On December 21, 1872, HMS Challenger set sail from Portsmouth, England, under the command of Captain George Nares. The vessel embarked on a 68,890-nautical-mile voyage to explore the world's oceans in unprecedented detail. Over nearly four years, Challenger scientists collected data on deep-sea temperatures, currents, marine life, and seabed geology. The expedition culminated in the publication of the 50-volume 'Challenger Report,' revolutionizing oceanography and marine biology. Many new species were discovered, and the term 'oceanography' gained widespread acceptance. The Challenger expedition remains one of history's most influential scientific journeys.
1872 Challenger expedition HMS Challenger George Nares Portsmouth, England