Raynaldus as mathematician

The Hindu-Arabic number system was invented in India around the year 500 AD, and during the Early Middle Ages spread throughout Arabic-speaking world. It reached into Western Europe by the end of the 10th century, and started getting more use in the 13th century. In his article “Old-Fashioned versus Newfangled: Reading and Writing Numbers, 1200-1500,” math historian John Crossley (Monash University, Australia, Studies in Medieval and Renaissance History, Third Series, Volume 10 2013) explains that even by the end of the Middle Ages many writers had difficulty understanding how numbers worked, and preferred using Roman numerals. With Roman numerals they would know that the various characters had a fixed amount. If they saw a V it would be five, X would be ten, and M that would mean one thousand.

“With minor exceptions, Roman numerals do not change their meanings when they change their place, but Hindu-Arabic numerals do.. When we encounter 3 in 437 or in 3,145,872, it means two different things. The distinctive feature of Hindu-Arabic numbers is their place notation, independent of the form of the numerals 0,1,…9.

The concept of place notation, along with new forms/symbols for numbers, proved difficult for medieval Europeans to understand, so changing over to the new system was slow. Crossley examined manuscripts from 1200 to 1500 to determine use of the Hindu-Arabic numerals, and found that in the 13th century, only 7% of manuscripts had the new numbers, rising to 17% for the 14th century and 47% for the 15th century. The impetus for changing to the Hindu-Arabic numbers in medieval Europe seems to have come from businessmen. Progressive and successful merchants such as those in our novels would have had to learn a major new approach to numbers

“Roman numerals were used in universities that taught about abstract properties ( square numbers, triangular numbers, etc.) and Hindu-Arabic numerals were used for commerce. They were taught in so-called abacus schools where merchants were taught the new Hindu-Arabic numerals. Such schools were prevalent in Italy. Since they were sometimes involved with quite complicated calculations, the commercial used ultimately led to the development of algebra. It was not until the 16th century that time academia embraced the study of methods of calculation, in particular algebra, while retaining its theoretical concern with abstract properties of numbers.”

Christian medicine

The influence of Christianity on medicine from Graeco-Roman times up to the Renaissance

By Francois Retief and Louise P. Cilliers

Acta Theologica, Vol.26:2 (2006)

In this overview of the effect of early Christianity on empirical medicine in Graeco-Roman times, it is shown that the first two centuries represented peaceful cooperation, since the Christians saw secular medicine as a legitimate form of supernatural cure and not as magic. Christianity brought caring communities with indiscriminate personalised care for the ill and aged. This ultimately led to the creation of hospitals as we know them today. Monastic institutions appeared which often had hospitals, and provided a degree of medical scholarship.

When Christianity became the state religion in the 4th century, the Church Fathers became increasingly authoritarian regarding the practice of medicine which was to be based on their interpretation of Galen. Progressive stagnation of scientific development and medicine specifically, set in. However, during the 5th century Nestorian Christians, fleeing from persecution by the Church, settled in Persia where they initiated a blossoming of medical science during the Golden Age of Islam (8th to 13th centuries), coexisting with the Dark Ages of Medieval Europe.

After this period Jewish and Christian doctors reintroduced Arabic versions of the works of the Greek masters from the teaching hospitals of Islam to the young European medical schools at Palermo and Montpellier. The Church which had in the mean time persisted with antiquated dogmas, resented the new teachings from heathen Islam, and responded with reactionary measures against supposed heretics, inter alia by instituting the Inquisition. But after the Reformation and Henry VIII of England’s break with the Vatican, the hegemony of the Church had come apart and Christianity and medicine gradually became realigned according to the realities of the Age of Enlightenment.

Treaty of Benevento

 After the Normans conquered Sicily, they had a hard time holding on to it. In 1155, Byzantine Emperor Manuel Comnenus reconquered parts of the southern Italian mainland. For Pope Adrian IV (the only English pope to date), having the Byzantines on its southern border was preferable to the troublesome Normans. In an alliance with Manuel, Adrian undertook to raise a body of mercenary troops to war against the Normans. But just as the war seemed decided in the allies' favor, things started to go wrong. The Greek commander, Michael Palaeologus, was recalled to Constantinople. He was a brilliant general in the field, and his loss was a major blow to the allied campaign. The turning point was the battle for Brindisi, where the Sicilians launched a major counterattack by both land and sea. At the approach of the enemy, the mercenaries deserted. Soon Adrian's Byzantine allies were left hopelessly outnumbered. William and his army landed on the peninsula and destroyed the Greek fleet (4 ships) and army at Brindisi on May 28, 1156. The Sicilian army approached Benevento where the pope was in residence, and the pope was forced to make terms, signing the Treaty of Benevento confirming William as king on June 18, 1156.

The kingship of William I of Sicily (William the Bad, 4^th son of Roger II) was recognized over all Sicily, Apulia, Calabria, and Campania, as well as Capua, the coastal cities of Amalfi, Naples, and Gaeta, and the newly conquered territories of Marche and the Abruzzi. The pope had to resign much claimed authority over the island. In the church of S. Marciano, William was invested by the pope with first Sicily, then Apulia, and finally Capua. In return, William paid tribute to the pope of 1000 schifati (similar to the Byzantine gold solidus).

New Year's Eve in the medieval world

http://www.medievalists.net/2015/12/31/celebrating-the-new-year-medieval-style/


Check out the new years celebrations in the medieval world at the above link.  The New Year wasn't always January 1.  In fact, in my notarial documents in Sicily, the official beginning of the year was March 1.  There were also other kinds of dating, especially regnal years when kings began their reigns, which were put in notarial records as well.


In Book #3 - The Leopard Triumphant, we talk about people drinking watered wine, which theoretically prevented people from being too drunk as the wine was usually drunk within the first year.  It was only in the next century that medieval people figured out how to age wine.


It's good to live in the 21st century, yes?!!

February 4, 1169

This date was the end for 15,000 to 25,000 people as a result of the earthquake in eastern Sicily and Calabria on the eve of the Feast of St. Agatha. Measuring 6.4 to 7.3 on various earthquake scales, this major temblor completely destroyed Catania, Lentini, and Modica, and was felt from Messina to Syracuse in Sicily and on the Calabrian peninsula. The quake triggered a tsunami on Sicily's eastern shore that moved large boulders and furthered the destruction. This large earthquake followed a period of increased seismic activity along the junction of the African plate and Eurasian plate. Fatefully, Sicily sits atop this junction. Some say the quake cause Mt. Etna to erupt, but more recent scholars say it didn't. Notably, the Cathedral in Catania collapsed, killing Bishop John of Ajello (Aiello) and 44 monks who had gathered for the feast day along with almost the entire population of the city. In the aftermath of the quake, officials feared that the exiled Tancred of Lecce and the Byzantines might capitalize on the situation with an invasion. Tancred, however, was allowed to return to Sicily and no invasion occurred. He went on to become king from 1189 to 1194. The poet Peter of Blois described the earthquake as Sicily's punishment from God for replacing his brother William of Blois as bishop of Aiello with John. John assumed the see in 1167 and died in the collapse of the cathedral.