On This Day
·

Treaty of San Germano between Emperor Frederick II and Pope Gregory IX

The Treaty of San Germano was signed on 23 July 1230 at San Germano, present-day Cassino, ending the War of the Keys that had begun in 1228.

The Treaty of San Germano was signed on 23 July 1230 at San Germano, present-day Cassino, ending the War of the Keys that had begun in 1228. The parties were Pope Gregory IX and Frederick II, king of Sicily and Holy Roman emperor. On 28 August at Ceprano, the peace was finalized with the readmission of the excommunicated Frederick into the church.

The negotiations for the treaty, initiated by Frederick, began in November 1229. The Lombard League, an ally of Gregory, objected to the process. The intercession of major German princes, especially Duke Leopold VI of Austria and Grand Master Hermann von Salza, was necessary to move things forward.

Historical Significance

The Treaty of San Germano was signed on 23 July 1230 at San Germano, present-day Cassino, ending the War of the Keys that had begun in 1228.

Events Before

  1. Holy Roman Emperor Frederick II crowns himself King of Jerusalem

    Frederick II (Italian: Federico, Sicilian: Fidiricu, German: Friedrich, Latin: Fridericus; 26 December 1194 – 13 December 1250) was King of Sicily from 1198, King of Germany from 1212, King of Italy...

  2. Queen Blanche of Castile & Earl Raymond VII of Toulouse sign peace

    Blanche of Castile (Spanish: Blanca de Castilla; French: Blanche de Castille; 4 March 1188 – 27 November 1252) was Queen of France by marriage to Louis VIII.

  3. Aragonese army led by James I of Aragon disembarks at Santa Ponça, Majorca, to conquer the island

    Aragonese army led by James I of Aragon disembarks at Santa Ponça, Majorca, to conquer the island

  4. Otto II becomes earl of Gelre

    Otto II becomes earl of Gelre

  5. James I of Aragon the Conqueror enters Medina Mayurqa (Palma) consummating Christian conquest of the island of Majorca

    James I of Aragon the Conqueror enters Medina Mayurqa (Palma) consummating Christian conquest of the island of Majorca

Events After

  1. Harderwijk (Netherlands) becomes a city

    Harderwijk (Netherlands) becomes a city

  2. Mongol army under General Subedei begins the siege of Chinese Jin capital of Kaifeng - 1st occasion gunpowder used in a

    Mongol army under General Subedei begins the siege of Chinese Jin capital of Kaifeng - 1st occasion gunpowder used in a major engagement

  3. Japanese legal code Goseibai Shikimoku or the Formulary of Adjudications is promulgated by Regent Hōjō Yasutoki

    Japanese legal code Goseibai Shikimoku or the Formulary of Adjudications is promulgated by Regent Hōjō Yasutoki

  4. Chinese city of Kaifeng, capital of the Jurchen Jin dynasty, surrenders to the Mongols under General Subedei after a sie

    Chinese city of Kaifeng, capital of the Jurchen Jin dynasty, surrenders to the Mongols under General Subedei after a siege of more than a year

  5. Otto II, Count of Guelders grants Arnhem the status of a city, it had previously belonged to the abbey of Prüm

    Otto II, Count of Guelders grants Arnhem the status of a city, it had previously belonged to the abbey of Prüm

More from the 1230s

English King Henry III marries Eleonora of Provence

English King Henry III marries Eleonora of Provence

Battle of the Sit River: Mongol forces of Batu Khan overcome Russians under Yuri II of Vladimir-Suzdal near Yaroslavl in

Battle of the Sit River: Mongol forces of Batu Khan overcome Russians under Yuri II of Vladimir-Suzdal near Yaroslavl in Russia, ending Russian resistance

Treaty of York is signed between Kings Henry III of England and Alexander II of Scotland, establishing a boundary betwee

Treaty of York is signed between Kings Henry III of England and Alexander II of Scotland, establishing a boundary between the two countries that remains mostly unchanged in modern times

Mongolian forces led by General Batu capture and burn the important Russian city of Vladimir, after an eight-day siege

Mongolian forces led by General Batu capture and burn the important Russian city of Vladimir, after an eight-day siege

Frequently Asked Questions

What happened on July 27, 1230?
The Treaty of San Germano was signed on 23 July 1230 at San Germano, present-day Cassino, ending the War of the Keys that had begun in 1228. The parties were Pope Gregory IX and Frederick II, king of Sicily and Holy Roman emperor. On 28 August at Ceprano, the peace was finalized with the readmission of the excommunicated Frederick into the church.
Why is Treaty of San Germano between Emperor Frederick II and Pope Gregory IX significant?
The Treaty of San Germano was signed on 23 July 1230 at San Germano, present-day Cassino, ending the War of the Keys that had begun in 1228.

Explore More

July 27 in HistoryYear 1230