John II of Portugal

John II of Portugal
c. 1455 – October 1495

John II of Portugal was born around 1455 to King Afonso V of Portugal. Descending from King John I, Prince John was a fourth-generation member of the Aviz dynasty. As his father’s only surviving son, the prince became heir apparent upon his birth. During the 1470s, John gained military experience while participating in his father’s African campaign. The king later entrusted the prince with further exploring Africa on Portugal’s behalf.


In April 1475, Afonso V declared war on Isabella I of Castile. The king desired to claim the Castilian throne and appointed John as his regent. Eventually, the prince assembled an army to assist his father. However, the Battle of Toro in March 1476 halted Afonso’s advance into Castile. Desperate for help, the king departed to France to seek an alliance with King Louis XI.

While his father was in France, John successfully defended Portugal’s border against Castilian attacks. After being rejected by Louis XI, Afonso V returned to his kingdom. Distressed at his failure, the king offered to abdicate. Although proclaimed as king, John’s father quickly changed his mind. Before he died in August 1481, Afonso agreed to a disadvantageous treaty with Castile.

King of Portugal

Upon his accession, King John II had to honor the Treaty of Alcacovas. As part of the agreement, the king placed his son, Afonso, under Spanish guardianship. This acted as a promise for him to one day marry a Castilian. John also had to deal with a powerful Portuguese nobility, especially the Braganzas. Under Afonso V, the house of Braganza had flourished. Due to this, their wealth and influence rivaled the monarchy.

Feeling threatened by the nobility, John II called for an assembly in November 1481. During the meeting, the king demanded that his nobles swear an oath of loyalty to him. John made it clear to his nobles that their disobedience wouldn’t be tolerated. Despite the Duke of Braganza swearing his allegiance, the king remained suspicious of him.

The Braganzas

In 1483, evidence emerged that proved that the Braganzas had contact with Castile. The documents showed that both sides had been conspiring against John II. In response, the king imprisoned the Duke of Braganza. In June, the duke went to trial and was found guilty of treason. As a result, the duke lost his head.

As a further show of dominance, John II confiscated the Braganza’s numerous estates. The king also dispersed royal judges throughout the nobility’s lands. By doing this, the king centralized royal authority at the nobility’s expense. In August 1484, disgruntled nobles began plotting to overthrow John. Upon discovering the conspiracy, the king personally killed their leader, the Duke of Viseu. In return, the nobility finally submitted to John.


Afonso V of Portugal
Afonso V of Portugal

After humbling the nobility and regaining Prince Afonso, John II turned his attention towards Africa. During Afonso V’s reign, the king saw Africa as something to be conquered. To this end, Afonso engaged in military campaigns against Morocco. However, John viewed Africa differently. Recognizing its economic potential, the king began funding African explorations.

During the 1480s, Portuguese explorers discovered the Congo River and explored southern Africa. Fortresses were also created to maintain Portuguese control. In 1493, Christopher Columbus returned to Europe. When Pope Alexander VI granted Spain all the lands that were discovered, John protested. In response, Spain and Portugal signed the Treaty of Tordesillas. The treaty would unknowingly allow Portugal to claim Brazil in the future.

Death of Prince Afonso

Throughout John II’s reign, Prince Afonso remained his only legitimate child and heir. The king had high hopes for his son and groomed him to be his successor. However, tragedy struck the royal family in 1491. On July 12, the prince died in a riding accident. Now without an heir, the devastated king faced a succession crisis.

Initially, John II considered legitimizing his illegitimate son, Jorge. Having promised the succession originally to his cousin Manuel, the king quickly abandoned Jorge. Despite accepting Manuel, John remained suspicious of him. Manuel’s older brother was the duke of Viseu. After Viseu’s death, Manuel feared being executed too. Fortunately for him, the king spared his cousin’s life.

Final Years

During the 1490s, John II’s health began to decline. In May 1492, the ailing king dealt with his final crisis. The Spanish monarchs, Ferdinand and Isabella, decided to expel all Jews to create an entirely Christian kingdom. As a consequence, many Spanish Jews sought refuge in Portugal. John allowed them to reside in Portugal for eight months temporarily. However, the king demanded a substantial payment from them in return.

When refugees couldn’t pay or didn’t emigrate in time, John II of Portugal retaliated against them. As punishment, Jewish parents had their children taken from them. The children would either be forced to become Christians or sent to populate overseas colonies. As a result of this harsh treatment, only 600 Jewish families remained intact in Portugal. In October 1495, John finally succumbed to his illness and died at 40.


John II was one of Portugal’s greatest kings. During his reign, John aggressively asserted his authority over the Portuguese nobility. After causing the downfall of the powerful Braganzas and overcoming a conspiracy, the nobility submitted to him. The king also funded and encouraged exploration. Despite the troubling end to his reign, John successfully laid the groundwork for his successors to build on.


Disney, A. R. (2009). A History of Portugal and the Portuguese Empire: From Beginnings to 1807 (Vol. 1). New York City, NY: Cambridge University Press.

Livermore, H. (2020, January 01). John II. Retrieved May 01, 2020, from


Andy Tree

I'm a European history enthusiast who seeks to share his passion with others. I hope to inform and inspire readers with my posts!

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