Princess Leonor joined her parents, King Felipe and Queen Letizia, on a trip to Navarre on Friday.
The historic visit marks the heir's first official royal trip to the Autonomous Community.
On Friday, September 26, the official Instagram account of the Spanish Royal Family shared a carousel of clicks from the two-day trip, which aims to underscore Leonor's ties to the region as she holds the title Princess of Viana.
The social media post was captioned, "This afternoon the Kings and Princess of Asturias [Kingdom of Castile] and Vienna [Kingdom of Navarre] presided over the tribute to the Kings of Navarra and the Kingdom of Navarra at the Monastery of Leyre (Yesa municipality)."
Furthermore, the Royal Family was joined by regional authorities and Benedictine community members, as they honoured the monarchs of Navarre, whose remains are preserved in a neo-Gothic oak box placed along one of the church's side chapels.
For the trip, the mother-daughter duo were donned in stunning suits; Letizia opted for burgundy, while Leonor looked gorgeous in navy blue as they attended the Government Palace of Navarre.
According to Navarra.com, Princess Leonor told a member of the public she was "very happy" while taking a selfie.
The official trip with her family came as the 19-year-old princess began her final year of military training as a future captain general of the Armed Forces when she accedes to the throne.
The Princess is following in the footsteps of her father, King Felipe, who took a similar path with his own military training in the late 1980s and early 1990s.
