What was the official language used across European monarchies in the XII century?

Question

I have been reading about European history in the XII century and I am finding out that several of the modern day languages hadn't yet evolved to what they are now: Langue d'oïl was still being used in France & Belgium, Old Saxon was still in vigor as well as Anglo-Saxon and Old East Slavic / Old Russian.

Was there an "official" language among monarchies just as English is nowadays for most governments? There were already agreements, marriage pacts and even crusades planned among different monarchies so they must have established communication somehow... I'm leaning towards the equivalent of French at the time, however I couldn't get any official sources to confirm this.

Wikipedia lists some of the monarchs of the time here: 12th-century monarchs in Europe

Answer 1

When it comes to western Europe, medieval Latin would be closer to an "official" language, especially for international affairs. The Roman Catholic Church's power and influence at the time was unparalleled and several major events of the era started with a Papal Bull. Here's a short list of Papal Bulls that were political in nature and were addressed, formally or informally, to the monarchs of the era:

• Sicut Judaeis (1120): Provides protection for the Jews who suffered from the hands of the participants in the First Crusade,
• Omne Datum Optimum (1139): Endorses the Knights Templar,
• Quantum praedecessores (1145): Calls for the Second Crusade,
• Laudabiliter (1155): Gives the English King Henry II lordship over Ireland,
• Manifestis Probatum (1179): Recognition of the kingdom of Portugal and Afonso Henriques as the first king,
• Audita tremendi (1187): Calls for the Third Crusade,
• Cum universi (1192): Defined the Scottish Church as immediately subject to the Holy See,
• Post Miserabile (1198): Calls for the Fourth Crusade.

Several other historical documents of the 12^th century are written in medieval Latin, even if not issued by the Pope or the Roman Catholic Church. For example:

• Instituta Cnuti (between 1066 and 1124),
• Quadripartitus (1100-1135),
• Leges Henrici Primi (1115),
• Leges Edwardi Confessoris (1140),

One document that stands out is the Charter of Liberties (1100), a forerunner to the Magna Carta. While apparently the original was most probably written in Latin, several copies of it were made in other languages depending on the intended audience, and all could have been considered authoritative at the time. The Magna Carta itself though was originally issued in Latin (and 15 years into the 13^th century), and then translated to French.

In the east, however, Byzantine Greek had replaced Latin as the official language of the Byzantine Empire since 620, when Emperor Heraclius started styling himself as Βασιλεύς¹ instead of the Latin Augustus. Official documents of the era were written in Byzantine Greek, although it's not unreasonable to assume that at least some of the documents that were addressed to European Monarchs would be written in medieval Latin.

Given that "official" at the time mostly meant sanctioned by the church, either the Roman Catholic Church or the Eastern Orthodox Church, I'd say that medieval Latin and Byzantine Greek would be very close to what we would today consider official languages.

_{¹ King; sovereign.}

Answer 2

According to wikipedia, Anglo-Norman French (the dialect of French spoken by the Norman conquerors) was used for that purpose in England in the 13th century. Before that it was typically Latin, and afterwards English.

(BTW: langues d'oïl basically means a dialect of French where oui is used to mean "yes". Anglon-Norman French was in fact one of those).

For diplomatic communications, Latin was generally used. Remember that the "Romance Languages" (French, Italian, Spanish, Romanian, etc.) were just regional dialects of Latin that slowly drifted into mutual-unintelligability.