King Pedro I of Portugal, also known as Pedro I of Portugal, ruled from 1357 to 1367. He was the son of King Afonso IV and became known for his efforts to strengthen the monarchy and improve the kingdom's administration. His reign was marked by conflicts with the nobility and efforts to assert royal authority. Pedro I is often remembered for his tragic love story with Inês de Castro, a noblewoman he secretly married. After her death, he declared her queen posthumously, leading to a dramatic and symbolic act of vengeance against her murderers. His reign left a lasting impact on Portuguese history.