In 1526, Dauphin Francis of France was exchanged with his brother as a hostage for his father, King Francis I, after the Battle of Pavia. This event impacted Franco-Spanish relations.
TIL After Francis I exchanged himself in spanish captivity in 1526 with his two sons, aged 7 and 8, he annuled everything he signed in exchange for his release, but the kids remained in captivity for nearly 4 years. His eldest son and heir was scarred for life as a result
