Blog

Blogs, essays, updates, and occasional notes that sit alongside The Butterfly Effect.

Painting of the assassination of Ali ibn Abi Talib at the Great Mosque of Kufa in 661.

The First Imam

Jan 26, 2026 By Andy Barca

On 26 January 661, Ali ibn Abi Talib was struck down during morning prayer by a former follower who couldn't forgive him for agreeing to negotiate. He was the last Rashidun caliph and the first Shia imam. His death split Islam in two.

Map of the Great and Little Zab rivers in northern Iraq, near the site of the Battle of the Zab in 750.

The Black Banners

Jan 25, 2026 By Andy Barca

On 25 January 750, the Abbasid rebels crushed the Umayyad Caliphate at the Battle of the Zab and then killed almost every member of the ruling dynasty. Almost. One prince swam a river and didn't look back — and built medieval Spain.

Bust of Emperor Claudius, proclaimed by the Praetorian Guard after Caligula's assassination in AD 41.

The Man Behind the Curtain

Jan 24, 2026 By Andy Barca

On 24 January AD 41, the Praetorian Guard assassinated Caligula and proclaimed Claudius emperor. Rome expected a joke. It got thirteen years of competent government instead.

Seated court portrait of the Hongwu Emperor (Zhu Yuanzhang), founder of the Ming dynasty.

The Beggar King

Jan 23, 2026 By Andy Barca

On 23 January 1368, Zhu Yuanzhang proclaimed himself the Hongwu Emperor and founded the Ming dynasty. He had been born to a destitute peasant family, orphaned by plague, and spent his teens wandering as a mendicant monk. He ended a century of Mongol rule over China.

Portrait of John VI of Portugal, prince regent who led the court's transfer to Brazil in 1808.

The Court That Sailed Too Well

Jan 22, 2026 By Andy Barca

On 22 January 1808, the Portuguese royal court arrived in Brazil after fleeing Napoleon. The colony became the empire's capital, Britain got the trade access it had always wanted, and Portugal spent a decade governing itself from the wrong continent.

Contemporary print of the execution of Louis XVI by guillotine at the Place de la Révolution, 21 January 1793.

The Day France Killed Its King

Jan 21, 2026 By Andy Barca

On 21 January 1793, Louis XVI was executed at the Place de la Révolution. The vote for his death passed by 361 to 319 - a margin of forty-two deputies. What followed made the king look like the easy part.

1860 map of Barcelona's Ciutat Vella (old city), the medieval core where the Llotja de Mar stands.

The Table Where Money Became Municipal

Jan 20, 2026 By Andy Barca

On 20 January 1401, Barcelona's city council opened the Taula de canvi in the Llotja de Mar - a public bank that guaranteed deposits with tax revenue, cleared payments by ledger, and showed what happens when a state treats its own credit as infrastructure.

Anton von Werner's painting of the proclamation of the German Empire at Versailles on 18 January 1871.

Forty-Eight Years in the Hall of Mirrors

Jan 18, 2026 By Andy Barca

On 18 January 1871, the German Empire was proclaimed in the Hall of Mirrors at Versailles. On 18 January 1919, the Paris Peace Conference opened in the same city. Between those two dates lived the full arc of German power — born in a defeated enemy's palace, ended in the same city by men determined to make sure it never happened again.

Marble bust of Emperor Theodosius I, last ruler of a united Roman Empire.

After Theodosius

Jan 17, 2026 By Andy Barca

On 17 January 395, Theodosius I died in Milan - the last man ever to govern a united Roman Empire. He left it to two sons, aged seventeen and ten. They never put it back together.