The "Barons of Runnymede" refers to a group of rebellious nobles who opposed King John of England in the early 13th century. In 1215, they confronted the king over his heavy taxation and arbitrary rule, leading to the creation of the Magna Carta, a foundational document that limited the powers of the monarchy and established certain legal rights. The meeting took place at Runnymede, a meadow near the River Thames. The barons sought to protect their privileges and ensure justice, marking a significant moment in the development of constitutional governance. The Magna Carta is often seen as a precursor to modern democracy and the rule of law.