Aeterni regis facts for kids

The papal bull Aeterni regis (which means "Of the eternal king" in English) was an important official document. It was issued by Pope Sixtus IV on June 21, 1481. This document officially approved and confirmed the main points of the Treaty of Alcáçovas. It restated that Castile owned the Canary Islands. It also granted Portugal rights to all new lands discovered by Christian powers in Africa and eastward towards the Indies.

Why This Document Was Needed

The Aeterni regis bull was issued after a big disagreement. This disagreement was called the War of the Castilian Succession. It was fought between Portugal and Castile from 1475 to 1479. The war was about who should become the next ruler of Castile. The two main people who wanted to rule were Joanna and Isabella. Joanna was married to Afonso V of Portugal. Isabella was married to Ferdinand II of Aragon.

Disputes Over the Atlantic Ocean

Besides the fight for the throne, there were also long-standing arguments. Both kingdoms wanted control over parts of the Atlantic Ocean. They both claimed ownership of the Canary Islands. They also both wanted control over the West Coast of Africa. Castile was good at land battles. However, Portugal had a strong advantage at sea.

The Treaty of Alcáçovas

To end the war, both sides decided to talk things over. Beatrice, Duchess of Viseu, who was a cousin to Afonso V and an aunt to Isabella, helped them negotiate. They signed a peace agreement called the Treaty of Alcáçovas. This happened in Alcáçovas, Portugal, on September 4, 1479.

Key Points of the Treaty

• Each side agreed to give up any claims to the other's kingdom.
• The agreement included parts of an older agreement from 1431. This involved returning certain places and releasing prisoners.
• Portugal gave the Canary Islands to Castile.
• Castile, in return, recognized Portugal's ownership and trading rights. These rights covered the Azores, Madeira, the Cape Verde Islands, and the coast of Guinea.
• If anyone broke the rules of the treaty, they would have to pay a large fine.

The Tercerias de Moura Agreement

There was also another agreement made at the same time. It was called the "Tercerias de Moura." This agreement arranged a marriage between Afonso V's grandson, Alfonso, and Isabella of Castile's oldest daughter, also named Isabella. The children were to live in a town called Mouros. This town was near the border of both kingdoms. They would stay there under the care of Dona Beatrice until they were old enough to get married.

The treaty also stated that both sides promised to follow its rules. They swore an oath not to ask the Pope or his representative to cancel their promise later.

Portugal's Goals After the Treaty

On May 4, 1481, King Afonso V of Portugal gave his son, Prince Joao, rights to trade and fish in Guinea. He also said that no one could go there without the prince's permission. By the end of August, Prince John became king after his father. His main goal was to find a sea route to the East.

The Pope's Approval

The Aeterni regis bull confirmed earlier papal documents. One of these was Romanus Pontifex, issued by Nicholas V in 1455. The new bull also included all the terms that Portugal and Castile had already agreed to in the Treaty of Alcáçovas. This gave the treaty a strong moral backing. It made the territorial division between the two kingdoms even more official.

Historians like Malyn Newitt have noted that Portugal's empire grew easily. This was because other powerful countries were busy with their own problems. Isabella and Ferdinand were fighting the Granada War. England was dealing with its own family conflicts. Louis XI of France was focused on matters in Italy. This allowed Portugal to expand without much challenge.

See also

In Spanish: Aeterni regis para niños

• Catholic Church and the Age of Discovery
• Treaty of Tordesillas (1494)