Alfonso X el Sabio

King Alfonso X was born in Toledo in late 1221 as the firstborn son of King Ferdinand III of Castile. He began training as a soldier at the age of sixteen under his father’s guidance and fought with him in several successful campaigns during which they took Murcia, Alicante and Cádiz from the Moors.  At first, he was only heir to the crown of Castile, but his father united the kingdoms of Castile and León when he was nine, and he became the prince of two kingdoms.

When Theobald I of Navarre was crowned, Alfonso’s father tried to arrange a marriage with Theobald’s daughter, but Alfonso had already fallen for Mayor Guillén de Guzmán, who bore him a daughter, Beatrice. The couple married in 1240, but they were forced to annul the marriage, and Beatrice was declared illegitimate. Nine years later, 28 years-old Alfonso was married to 13 year-old Violante of Aragon. For the first few years of the marriage, poor Violante was too young to be a wife, but after puberty, several years passed without any sign of pregnancy. Alfonso considered writing to the Pope asking to annul the marriage, but during one of the campaigns against the Moors in Alicante, legend says that the king and queen spent a few nights resting in a small farm in the countryside, and during their stay, she became pregnant with their first son, Ferdinand. Grateful Alfonso called the farm the "the plain of good sleep" or "pla de bon repos" Now a  suburb of Alicante, it is still known by this name today. 

It was while he was serving in the army with his father that, young Alfonso was struck with the code of chivalry and mutual respect between knights. He soldiered with Perez de Castron, a friend of his father, and what the old knight taught him, and he subsequently saw in battle, left a lasting impression on the young prince. He wrote later that during a battle to take Jerez, he had a vision of St. James mounted on a white horse holding a white banner in the sky above Castilian troops. This revelation appears to have formed his later opinions on law and the conduct of nobility. 

In 1252, upon his father’s death, he was crowned King of Castile and León and his first act as king was to invade Portugal, forcing the greedy and avaricious King Afonso to surrender his kingdom. Clever Alfonso struck a deal with the Portuguese king, making him divorce his own wife and marry Alfonso’s illegitimate daughter Beatrice - or lose his kingdom. Poor Afonso had no option but to comply. This meant that Alfonso’s daughter would be queen of Portugal, and any children would inherit the crown of Portugal, but be allied to Castile and León.

In the same year, he also initiated a claim to Gascony, the only remaining English possession on the continent. The province was supposed to have been given as a dowry for the hand of Eleanor of England when she married Alfonso VII of Castile in 1174. There are no written records of the dowry, so it is a doubtful claim. However, King Alfonso immediately pursued it with the current English monarch, Henry III, and offered to support him in his war with France. The English King was only too happy to arrange a deal in which his son and heir, Edward I, married King Alfonso’s half-sister, another Eleanor, to become Queen Eleanor of Castile.

During the same period as these arranged marriages were taking place, King Alfonso also dealt with a rebellion amongst his nobles. Two very powerful families jockeyed for his favour and their gain. Nuño González de Lara and Diego López de Haro were dangerous lords who controlled vast estates and could raise their own private armies. During his reign, King Alfonso had to play them off against each other in an endless battle of wits and strategy. These were not the only two powerful families wrestling for power, nor were they only Castilian families. The Moors courted and plotted constantly with the disaffected Christian factions in an attempt to undermine Alfonso’s crown.

You would think that King Alfonso would become a bitter man hardened to the threats all around him, but his deeds have shown him to be quite the opposite. When he was a prince, Alfonso harboured many ambitions, but his greatest contribution to history was not in conquest or gain, but in literature, law-making, science and astronomy. He showed a marked flair for academic studies, and while he was still a prince, he helped with the work of the scholars by enlarging and supporting the Toledo school of translators. This was a group of Arabic and Jewish translators working on the ancient tomes that were stored on the shelves in colleges all over Toledo.


Kalila wa Dimna


When the Christians moved into the city they discovered the work that was going on in the Muslim madrasas, or universities.  One of the pillars of the Muslim faith is education, and the relentless quest of self-improvement was evident in the Arabic culture. During its rapid rise, Islam had gathered the wisdom of a dozens of empires and cultures. Rather than destroy their written records, they had collected them, and were in the process of translating and teaching their wisdom to their followers.

Until then, the common language for writing around Mediterranean was Latin, thanks to the Roman Empire. But Alfonso encouraged the translators to use the nascent Castilian tongue as a base language. Of course, it employed the same Latin forms for the verbs, but was enriched by a huge vocabulary of Arabic words. Modern Spanish still uses the basic form that Alfonso encouraged his translators to use. His father had begun this conversion from Latin to Castilian, and increasingly, the dealings of courts and commercial transactions were recorded in Castilian rather than Latin.

Prince Alfonso’s first translated work was Calila e Dimna which was translated from an old Arabic text, Kalila wa Dimna, which in turn was translated from an eighth-century translation by Ibn al-Muqaffa taken from a Middle Persian version of the Sanscrit Panchatatntra written around 300. It is an instruction manual in wisdom for young princes, and uses a series of questions and answers between an ox, a lion and two jackals called Calila and Dimna. Like Aesop’s fables, it uses allegorical examples to illustrate the lessons, and encourages the pupils to answer the questions for themselves.

Alfonso’s next effort was written in 1255, only three years after he had been crowned, and was meant to be of more practical value. The Fuero Real was without doubt all Alfonso’s work, and was a basis for the laws of his kingdoms and a textbook for the judiciary to follow in their day-to-day decisions.

By far his most comprehensive legal work was completed in around 1265. The Siete Partidas was an effort to codify the correct conduct for knights. It was unique for the time because it incorporated theological statements to cover the different religions that his kingdoms encompassed.  More a universal encyclopedia for the governing of such different cultures, it incorporated philosophical and moral issues taken from Judean, Christian and Islamic teachings. On a more practical level, it guided the behavior of his knights in carrying out their duties, stressing “good lineage, gentility, wisdom, understanding and the practical knowledge to necessary to assess the quality of horse and arms.”

In truth, Alfonso probably had little to do with the actual writing, but certainly guided and edited the final work. It was probably written to impress the Catholic Church, because Alfonso was pursuing his own private goal of becoming the King of the Holy Roman Empire.  He had inherited his eligibility for this greatest of all honours from his father, but the cardinals in the Holy City extracted bribes and gifts from the not-so-wise king until in 1275 the Pope asked him to abandon all claims. The warring nobles in his own kingdom spurned the Siete Partidas and it was only when his grandson Alfonso XI revived the laws nearly a hundred years later that they were widely adopted.

One outcome that Alfonso could never have imagined was that his laws would be used to govern Spain’s post-Columbus South American possessions, and are still a large part of their present day legislation. As a final recognition of Alfonso’s wisdom, his portrait hangs in the US House of Representatives chamber, along with 22 other lawmakers who are honoured there.


By far the most important legacy that King Alfonso X left was in the sciences. Amongst the thousands of books that dated back to the beginning of writing were treatises on astronomy, astrology, medicine and chemistry. As soon as they were translated, they were compiled and refined by the learned men of the day.

The Almagest, or to give it its English translation, “The Greatest,” was written around 150 by the Greek astronomer, Claudius Ptolemy. It was taken from an earlier work from around 350 BCE by the Greek philosopher Aristotle, who was a profound thinker on just about every subject then known.

 The Alfonsine tables

Three hundred years after Ptolemy, the Persian astronomer Al-Sufi corrected many of Ptolemy’s original observations. To this was added the corrections of al-Andaluz astronomer al-Zarqali, and finally, what lay before King Alfonso’s translators was the sum total of all the world’s knowledge of astronomy in one place, and written in Castilian.

That would be enough of an achievement for most scholars, but King Alfonso ordered his astronomers to create another set of tables from their own observations that accurately predicted the motion of the visible planets against the fixed stars. These he added to the Almagest as the Alfonsine tables.

Just over two hundred years after King Alfonso died, Nicolaus Copernicus had a copy of the Alfonsine tables with him when he was studying in Kraków. The accurate measurements helped him form his own heliocentric theory, which places the sun in the centre of the solar system. In recognition, Copernicus had one of the craters on the Moon named after him, but Alfonso the Wise was not forgotten, and he has one named after him, too. Much later, in 1675, an English mathematician called Isaac Newton would quote an older proverb by saying: “If I have seen further it is by standing on the shoulders of Giants.” This sums up King Alfonso’s contribution to science.