Battle of Aljubarrota - Prelude

Prelude

The end of the 14th century in Europe was a time of revolution and crisis, with the Hundred Years' War devastating France, the Black Death decimating the continent, and famine afflicting the poor. Portugal was no exception. In October 1383, King Ferdinand I of Portugal died with no son to inherit the crown. The only child of his marriage with Leonor Telles de Menezes was a girl, Princess Beatrice of Portugal.

In April of that same year the King signed the Treaty of Salvaterra de Magos with King Juan I of Castile. The treaty determined that Princess Beatrice was to marry Juan I, king of Castile, and the Crown of Portugal would belong to the descendants of this union. This situation left the majority of the Portuguese discontent, and the Portuguese nobility was unwilling to support the claim of the princess because that could mean the incorporation of Portugal to Castile; also the powerful merchants of the capital, Lisbon, were enraged from being excluded from the negotiations. Without an undisputed option, Portugal remained without king between 1383 and 1385, in an interregnum known as the 1383–1385 Crisis.

The first clear act of hostility was taken in December 1383 by the faction of John (João), the Grand Master of the Aviz Order (and a natural son of Peter I of Portugal), with the murder of Count Andeiro. This prompted the Lisbon merchants to name him "rector and defender of the realm". However, the Castilian king would not relinquish his and his wife's claims to the throne. In an effort to normalize the situation and secure the crown for him or Beatrice, he forced Leonor to abdicate from the regency. In April 1384, in Alentejo, a punitive expedition was promptly defeated by Nuno Álvares Pereira, leading a much smaller Portuguese army at the Battle of Atoleiros. This marked the first use of English defensive tactics on the Iberian peninsula, reportedly without any casualties to the Portuguese. A larger second expedition led by the Castilian king himself reached and besieged Lisbon for four months before being forced to retreat by a shortage of food supplies due to harassment from Nuno Álvares Pereira, and the bubonic plague.

In order to secure his claim, John of Aviz engaged in politics and intense diplomatic negotiations with both the Holy See and England. On 6 April 1385, (the anniversary of the "miraculous" battle of Atoleiros, a fortuitous date), the council of the kingdom (cortes in Portuguese) assembled in Coimbra and declared him King John I of Portugal. After his accession to the throne, John I of Portugal proceeded to annex the cities in whose military commanders supported Princess Beatrice and her husband's claims, namely Caminha, Braga and Guimarães among others.

Enraged by this "rebellion", Juan I ordered a host of 31,000 men to engage in a two-pronged invasion in May. The smaller Northern force sacked and burnt populations along the border, including the open city of Viseu, before being defeated by local Portuguese nobles in the battle of Trancoso, on the first week of June. On the news of the invasion by the Castilians, John I of Portugal's army met with Nuno Álvares Pereira, the Constable of Portugal, in the town of Tomar. There, they decided to face the enemy in battle, before they could get close to Lisbon and besiege it again.

Along with its English allies who arrived on the 1385 Easter, consisting of a company of about 100 English longbowmen, veterans from the Hundred Years War, sent to honor the 1373 alliance (presently the oldest active treaty in the world). The Portuguese set out to intercept the invading army near the town of Leiria. Nuno Álvares Pereira took the task of choosing the ground for the battle. The chosen location was São Jorge near Aljubarrota, in a small flattened hill surrounded by creeks, with the very small settlement of Chão da Feira (Fair's Ground) at its widest point, still present today.