The five members of the English parliament that Charles I attempted to arrest on 4 January 1642. Mounting opposition to the king, culminating in the Grand Remonstrance (December 1641), had been led by Pym, supported by Hampden, Holles, Hesilrige, and Strode. Charles rashly decided to arrest and impeach them. He entered the House of Commons only to find that the members had fled into the City of London; they returned to the House of Commons a week later. This attempted use of force by the king hardened Parliamentary opposition against him and was a factor leading to the outbreak of the English Civil War. No other monarch has since set foot in the House of Commons; its independence from interference is fundamental to its existence.