Philippa of Lancaster was a Portuguese princess born in 1360, the daughter of John of Gaunt, the Duke of Lancaster, and his first wife, Blanche of Lancaster. She became the Queen of Portugal through her marriage to King John I of Portugal in 1387, which strengthened the alliance between England and Portugal during the Hundred Years' War. As queen, Philippa played a significant role in promoting peace and stability in her adopted country. She was known for her piety and charitable works, and she had several children, including Henry the Navigator, who would later become a key figure in the Age of Discovery.