1383 Portugal’s House of Avis

The House of Avis, Portugal’s second ruling dynasty after the House of Burgundy, rightfully gets credit for launching the Age of Discovery. It came to the forefront when King Fernando of Portugal died in October of 1383, just four months after the marriage of his daughter Beatrice to Juan I of Castile.

Beatrice was only eleven years old. Juan was twenty-five. In his will, Beatrice’s father, Fernando, left his wife, Leonor, and her lover, João Fernandes Andeiro of Galicia, in charge of Portugal. Leonor served as Regent for Beatrice. The scenario miffed King Juan I of Castile. He had not agreed to the regency plan. Fernando had promised him that Portugal would belong to the descendants of his union with Beatrice. Juan demanded to take his place as King of Portugal right away.

The Portuguese Crises of 1383 to 1385

King Juan I’s threat infuriated the Lusitanian Portuguese. They already hated the adulteress Leonor; many people suspected that Beatrice was Andeiro’s daughter, not Fernando’s. Nobody wanted Juan I of Castile to be the King of Portugal. In fact, the Portuguese wanted the Castilians out of their country altogether. So, looking for an alternative, they turned to Fernando’s half-brother, João of Avis. [John in English.]

We mentioned the birth of João of Avis (1358-1433) in our story about Pedro and Inês. Joao was Pedro’s illegitimate and only child from a mistress he had after Inês was murdered, Teresa Gille Lourenço. As we also mentioned, no one knows what happened to Teresa after João’s birth. King Pedro entrusted little João to the care of Teresa’s father, Lourenço, who was to make sure João was educated and brought up as a knight.

In 1364, when João was only seven years old, King Pedro anointed him Master of the Order of Avis, a military order similar to the Knights Templar, Knights of Santiago, and the Order of Christ. The order had been founded in Évora in 1146 by João’s great-great-great-great-great-great-grandmother Teresa, Countess of Portugal. She ordered the Castle of Avis built to guard Évora from the Moors to the south. Teresa’s son, Afonso Henriques appointed his illegitimate half-brother, Pedro Henriques, to serve as the order’s first Grand Master. The order’s clan color was green, and their emblem looked like this:

The sarcophagi shown below [carved later for João’s son, João, who will inherit the position of Master of Avis] is decorated with the order’s emblem [left] and the Portuguese crest [right].(1)

At the time of João’s half-brother Fernando’s death, João was twenty-seven years old. He had a lot of friends, especially with the middle class Lusitanians. And the position of Grand Master of the Order of Avis came with armed forces.

How João of Avis Took Control of Portugal

One night João and some of his knights/courtiers entered the dining room of his step-mother Leonor’s palace, the castle where she was living with Andeiro. After some discussion, João asked Andeiro to move with him to the privacy of another chamber. Once away from Leonor, João accused Andeiro of “working towards his dishonor and death.” Andeiro denied the charge. João bashed Andeiro in the head with a dagger. When the blow did not kill Andeiro, one of João’s knights thrust Andeiro through with a sword and finished the dastardly deed.

After some political maneuvering, Portugal’s legislature, the Cortes of Coimbra,(2) proclaimed João of Avis as Defender of Portugal. It would take João two more years to complete his takeover and graduate to King of Portugal as João I.

King João I and his compatriots immediately made some changes – an easier task after some of the lords who had been faithful to Leonor switched to King João I’s team:

In spite of Joao’s success at taking control of Portugal, King Juan I of Castile did not give up his quest for the Portuguese crown. Juan believed his wife Beatrice of Portugal to be the rightful heir. So he enlisted the support of the French, the Biscayans, and his mother-in-law Queen Leonor of Portugal. Leonor, who was also João’s step-mother, had fled to live with Juan and Beatrice in Seville in Castile. The combined Castilian and French forces marched on Lisbon.

Since the English were also enemies of the French, João sought the help of seventeen-year-old King Richard II to stand up against Juan I of Castile. Richard II, by that time, ruled England on his own. He sent his uncle, John of Gaunt, with the understanding that once Gaunt and João won, Gaunt and his wife, Constance of Castile, would take their rightful places as King and Queen of Castile and León. In addition, Richard supplied funds and ships.

Before the English left for Iberia, the Castilians and French surrounded Lisbon. Their siege lasted four months and would have succeeded had a bad case of the plague not ravaged their forces. The Castilians hauled 200 or more people a day back to Castile draped over donkeys and carts.

In May of 1385, the Castilians invaded Portugal again with two armies. One entered north of the Serra de Estrella [mountains] and burned several towns along the border before the armies of Portuguese nobles stopped them. Another approached south of the mountains. Worried that the southern invasion would siege Lisbon again, King João and the Constable of Portugal, Nuno Álvares Pereira (1360-1431) met at Tomar to devise a strategy to head them off. By that time, English forces had arrived to help. Under a blazing hot sun on August 14, 1385, the Portuguese army waited in a valley called São Gorge near Aljubarrota, which is between Leira and Alcobaça, where Alfonso Henriques had begun construction of Portugal’s largest cathedral centuries earlier.

Led by General Pereira, the Portuguese army was made up mostly of middle class merchants and artisans. King João I led the back-up forces in the rear. The Portuguese fought with sling shots, swords, and battle axes with the same determination their Lusitanian ancestors fought to keep the Romans out of Lusitania centuries earlier. One famous story from the battle claims that as the Portuguese beat the fleeing Castilian army east, the wife of a baker slew six Castilian soldiers with the iron scoop she normally used to push bread in the oven. Today, many restaurants in the vicinity of Batalha [which means Battle] claim to be Casa de la Padeira [House of the Baker].

King João ordered the construction of Batalha Monastery in the valley where his countrymen claimed victory and where he and his family will be entombed later.

Batalha Monastery guarded by a statue of General Nuno Álvares Pereira.(3)

Interior courtyard of the Batalha Monastery and the nave.(4)

Just a few notes about General Nuno Álvares Pereira: Not only was he instrumental in helping King João I maintain Portugal’s independence from Castile, but he fathered the House of Bragança, which, in 1610, will take control of Portugal back from the Spanish and rule until 1910. It appears that Pereira’s wife, Leonor Peres/Pires of Alvim, was related [possibly the sister] to King Joao’s mistress Inêz Peres/Pires (c.1350-c1400). General Pereira and Leonor’s only surviving child, Beatrice, will marry João’s natural son by Inéz [possibly his cousin], Afonso, the 1st Duke of Braganza, and together, they will start the line for the House of Bragança.

Treaty of Windsor

After the battle at today’s Batalha conclusively established Portuguese sovereignty, Juan I of Castile returned to Seville and King João of Portugal returned to Coimbra. But the Portuguese still felt vulnerable and the English still wanted one of their own sitting on the throne of Castile. In May 1386, the two countries arranged a diplomatic alliance that resulted in the Treaty of Windsor, whereby the countries would support each other.

Portugal agreed to back the English in their effort to wrench the crown of Castile from Juan I in favor of John of Gaunt and Constance of Castile. João loaned the English ten large Portuguese galleys for a period of six months. Each galley was manned by a master, three lieutenants, eight to ten sailors, sixty bowmen, and no less than one-hundred-eighty rowers. Gaunt’s own fleet of twenty ships, provided by his brother King Richard II, joined them in Galicia in July.

As part of the alliance, John of Gaunt offered to King João the hand of his daughter Catherine of Lancaster in marriage. João, who still had not met John of Gaunt or his daughter, politely refused. He claimed that his marriage to an heir of Castile – Catherine was Constance’s daughter and therefore the granddaughter of the murdered King Pedro – would compromise Portugal’s position as a separate entity. Instead, João asked for the hand of Philippa of Lancaster (1360-1415), John of Gaunt’s oldest daughter by his first wife, Blanche of Lancaster.

The family tree at the beginning of this article can help you sort this out. Both Catherine and Philippa were granddaughters of Edward III, King of England, who, let’s remember, was extremely interested in exploring the northern Atlantic.

João and Philippa married in the Sé [Cathedral] in Porto on St. Valentine’s Day 1387. João was twenty-nine years old and Philippa was twenty-eight.

The entrance and nave of Porto’s Sé.(5)

Clothed and crowned in gold, they paraded on white horses from Porto to Coimbra to take up residence. Note that even though this story is about the Portuguese, a key and important character is an English woman who had been taught how to use an astrolabe.

Within days of the wedding, John of Gaunt and João of Avis marched to Seville. On the way, their troops were overcome by another plague. The diminished forces reached Seville only to find the city well fortified and prepared for battle. Gaunt relented. In a secret maneuver, he signed a peace pact with Juan I of Castile. Gaunt gave up his own claim to the Castilian throne in exchange for the marriage of his daughter, Catherine of Lancaster [the woman João of Portugal had refused] to Juan I’s son and heir, Henry of Castile. [Catherine of Lancaster and Henry of Castile were second cousins.] This move placed Catherine in line to be Queen of Castile at the death of Juan. João of Avis returned to Coimbra.

In 1388, after his failed attempt to conquer Castile, King João I turned his efforts toward fighting the infidels in Granada and Africa. He and Philippa moved their residence to Sintra, just northwest of Lisbon. João traveled back and forth from the castle in Lisbon, but the plague infested cities were considered unhealthy for bringing up children.

Aside from its beauty and clean air, Sintra was a strategic place on top of a hill overlooking the Atlantic. The Moors had thought so too and built a castle that still crowns one of the highest peaks. From that peak, João had a view of Europe’s most western point, Cabo da Roca [Cape of the Rock], and beyond that the Atlantic. His watch-guards could easily see any vessels sailing in and out of Lisbon from the north. 

Facing west from the walls of the Moor castle in Sintra.(6)

The Illustrious or Marvelous Generation

During the next fourteen years,Queen Philippa [known in Portugal as da reinha, Doña Felipa de Lencastre] gave birth to nine children [six sons and three daughters].

  1. Blanche, born in July of 1388, died at eight months
  2. Afonso, born in 1390, died at age ten
  3. Duarte I [Edward in English and Latin, named after his maternal grandfather, Edward III of England], born in 1391, was the heir apparent and will live to age forty-seven
  4. Pedro [Peter in English], born in 1392, was the Duke of Coimbra, and will live to age fifty-seven.
  5. Henrique [Henry in English], also known as Anrique and Henry the Navigator, born in 1394, was the Duke of Viseu, the Grand-Master of the Order of Christ, and will live to age sixty-six.
  6. Isabella, born in 1397, will marry the Duke of Burgundy, Holy Roman Emperor, become a powerful empress, and live to age seventy-four
  7. Blanche, born in April 1398, dies that same year at three months old
  8. João, Constable of Portugal, born in 1400, will live to age forty-two. He will be the grandfather of Queen Isabella of Castile.
  9. Fernando, born in 1402, will become the Master of the Order of Avis, then a captive in Tangier where he will die age forty-one.

King João already had three children from the affair he had with Inês Peres before he married Philippa. One daughter died as an infant in 1379. Two children still lived.

  1. Afonso, born in 1377, was the Count of Barcelos and will become the first Duke of Bragança. He lives to the ripe age of eighty-four.
  2. Beatrice, born in 1382, moves to England to marry first the Earl of Arundel, and when he dies, marries the Earl of Huntingdon. She lives to age fifty-seven.

Inês Peres, mother of the House of Bragança, disappears from record. It is believed she lives until the year 1400, or there about, but King João has no more children with her.

João and Philippa paid special attention to educating their offspring. They included their sons in the government of the country. Philippa had learned to read and write, which was unusual for a woman in those days. Scholars and churchmen traveled frequently from her family’s home in Lancaster, England, to her homes with João in Sintra and Lisbon. She preached that a Christian’s first duty was to drive back the infidel. And she tried to instill morality in the court.

King João was also learned. He wrote a book titled Livro de Montaria about hunting bears, wolves, wild boar, deer, and hares. He believed hunting promoted health and was good training for soldiers preparing for battle.

House of Avis monarchs will control Portugal until 1581, when King Philip II [Queen Elizabeth of England’s arch rival] invades Portugal and claims both Portugal’s and Spain’s thrones for the House of Habsburg.(7)

The Princes Duarte, Pedro, Henry, João, and Fernando, as well as their sister, Princess Isabel, will be known as the Ínclita Geração [the Illustrious Generation or Marvelous Generation] because their dedication to the Reconquista and finding a route under Africa to the Far East resulted in the Age of Discovery. They will also connect to the most powerful monarchies in Europe.

All these relationships will become more helpful when, in 1411, Portugal and Castile sign a peace treaty.

If you are not yet overwhelmed by this family tree, here is a preview of how the House of Avis will relate to Queen Isabella of Castile and King Ferdinand of Aragon who will bless Christopher Columbus on his way to America:

  1. Catherine of Lancaster and Henry of Castile become the grandparents of Queen Isabella I.
  2. Juan I of Castile’s second son, Ferdinando (1380-1416), will become King of Aragon, Valencia, Sardinia and Majorca. Ferdinando will marry Eleanor of Albuquerque (1374-1435). The couple will become the grandparents of Ferdinando II of Aragon, who will, in 1469, marry the aforementioned Isabella I of Castile and unite the kingdoms of Castile and Aragon.

This next chart shows how both João II, who will reject Christopher Columbus’ proposal to cross the Ocean Sea, and Queen Isabella of Castile, who will accept it, descended from João of Avis.

This last chart shows how marriages in the House of Avis interconnected with the other monarchies in Europe for the first three generations.


  1. Photo of João of Avis’ sarcophagi ©2015 Mary Ames Mitchell. All rights reserved.
  2. The English word court comes from the Portuguese Latin word for council, cortes.
  3. Photo of Batalha Monastery and General Pereira ©2015 Mary Ames Mitchell. All rights reserved.
  4. Photo of Batalha Monastery Courtyard and Nave ©2015 Mary Ames Mitchell. All rights reserved. Both monasteries, Alcobaça and Batalha, are isolated from the typical tourists routes in Portugal and difficult to reach by public transportation.
  5. Photo of Porto’s Sé ©2015 Mary Ames Mitchell. All rights reserved.
  6. Photo of Moorish castle in Sintra ©2015 Mary Ames Mitchell. All rights reserved.
  7. Portugal did not earn her independence again until ten years after John Winthrop’s Fleet filled with Puritans left for America in 1630.

Next article: Henry the Navigator