The Treaty of Windsor was a pivotal agreement forged between England and Portugal, reflecting a mutual commitment to support each other in times of need. This alliance emerged during a period marked by territorial disputes and aspirations by neighboring powers, particularly France and Castile. Given the political context, both nations sought to bolster their defenses and secure their interests through collaboration. The treaty included provisions for military support and representation for both countries in the event of conflict, which would later become a cornerstone of their relationship.

King John I of Portugal and King Richard II of England played significant roles in the ratification of this document, signaling a move towards an enduring partnership characterized by loyalty and mutual respect. Over the following centuries, this alliance facilitated not only military cooperation but also cultural and economic exchanges, reinforcing the bond between the two countries.

The signing took place amidst the charged atmosphere of late medieval Europe, where alliances and rivalries were commonplace. The Treaty of Windsor set a precedent for international diplomacy, showcasing the potential for long-lasting political bonds based on shared interests and strategic advantages. As Europe evolved through various conflicts and alliances, the treaty remained a testament to the strong ties that persisted between England and Portugal across generations.