At the end of the 8th century, King Charlemagne's chief advisor, Adalgard of Corbia, wrote a handbook for the administrators who would rule Italy. The book titled “On the Palace Organization” allows you to see how military intelligence was organized under the Carolingian family. Medieval portal.net speakHow the intelligence of kings works.
Adalgard outlined several key methods by which the court could obtain information on a variety of factors, including military threats. He emphasized that anyone from the border region who comes to court must be questioned about what is happening in neighboring lands. The abbot advised paying special attention to Frankish tax payers. The ruler should have been warned as soon as possible if these people appeared dissatisfied and potentially preparing to rebel.
By the same logic, people traveling to lands beyond Frankish rule should have been interrogated for any useful information. Their words could reveal not only signs of hostility between foreign peoples but also details about shipping routes, water sources, and other topographical aspects that would be useful to the Carolingians during a possible invasion.
Although court guests and people from the border region could be useful sources of information in this situation, Adalgard emphasized the role of experts in planning military operations. He termed special advisors to the rulers praecipui consiliarii – meaning people with specific expertise in a particular field. Speaking specifically about military forces, he means people who know certain lands well.
Adalgard proposed that every year at the beginning of winter, the ruler convened a special planning group – the Magistratus. She is responsible for developing information on current and current adversaries for the purposes of planning military operations. Members of the magistracy were required to make their recommendations in documents known as capitula, the same word used to describe orders issued by Carolingian kings. In addition, the monk also insisted on absolute secrecy: each member of the council must keep the content of the document secret, not letting any of the ruler's secret plans be leaked to the enemy.
Narrative sources from the early 9th century reveal much about the type of person Adalgard considered a suitable candidate for the position of special advisor. So, in the biography of Louis I the Pious it is mentioned that the emperor regularly summoned commanders from the border to the court to report on the state of military operations. And supposedly one day one such commander, Count of Nantes Lambert I, convinced the court of the need for a military campaign.
In addition, the biography's author, former royal official Ermold Nigell, provides many details about the information provided by his advisors at the annual meeting in early 801. Charlemagne then planned to conquer the area that would become Catalonia and the fortress of Barcelona. For example, one of the advisors, Count Guillaume Gelonsky, presented a detailed report on the deployment of Muslim forces in Spain. He collected information about the fortifications of the Muslim garrison and the safest routes along which the army could move within their territory. According to this report, Nigella believes that the campaign against Barcelona has been successful.
Louis I the Pious's son, Louis II the German, also paid great attention to information gathering. In his case, what has survived to this day is not a retelling of the work of his advisors, but a kind of “finished product” of agents working on the king's orders. The eastern border of Louis II's kingdom extended nearly 1,000 km from the Elbe River to Isar. Along almost the entire border, he could face hostile (or potentially hostile) troops, and so the king regularly sent troops to the area.
In preparation for these campaigns focused almost entirely on sieges, Louis II requested detailed reports on the condition of the enemy's military assets. Such a text has survived to this day – “Description of the fortresses and areas north of the Danube” which is sometimes erroneously attributed to the pen of a certain Bavarian geographer. In total, the document lists 246 points. Intensive excavations by archaeologists at these sites have shown that many of the original fortifications were built in the early or mid-9th century.
