Victoria de Marichalar y Borbón celebrated her cousin Princess Leonor’s milestone birthday from Peru! The 23-year-old daughter of King Felipe’s sister Infanta Elena posted a tribute to the Princess of Asturias on her Instagram story.

Sharing a picture of Leonor from her birthday on Tuesday, Victoria wrote (translated to English): “Today is a great day for you and for Spain, I am sure you will become a great queen. I am very proud of you. Happy birthday!”

©Victoria de Marichalar de Borbón

Leonor swore an oath to the Spanish constitution in front of the Cortes Generales on her 18th birthday and was presented with the Collar de la Real y Distinguida Orden Española de Carlos III (The Royal and Distinguished Spanish Order of Charles III).

“I owe myself from today to all Spaniards, whom I will serve at all times with respect and loyalty,” she said in a speech after receiving the civil order. “There is no greater pride. On this important day - which I will always remember with emotion - I ask you to trust me, as I have placed all my trust in our future, in the future of Spain.”

In the evening, King Felipe and Queen Letizia hosted a private celebration for family at the Royal Palace of El Pardo. Leonor’s younger sister, Infanta Sofia, was pictured leaving the celebration with her mother Queen Letizia. The Princess’ paternal grandfather Juan Carlos I, grandmother Queen Sofia, Infanta Cristina and Infanta Elena were among the family members who attended the gathering.