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Why did Charles I’s attempt to arrest five members of Parliament fail?

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Painting of the Battle of Naseby shows cavalry and infantry clashing, with soldiers on horseback leading a charge and fallen fighters on the ground amid the chaos of battle. — English Civil Wars *Battle of Naseby*, by an unknown artist. The victory of the Parliamentarian New Model Army, under Sir Thomas Fairfax and Oliver Cromwell, over the Royalist army, commanded by Prince Rupert, at the Battle of Naseby (June 14, 1645) marked the decisive turning point in the English Civil War.

King Charles I’s attempt to arrest five members of the House of Commons and one member of the House of Lords on January 4, 1642, failed primarily because his plan was not kept secret.12

Because the intended targets were warned of the impending royal attack, they had already fled and hidden in the city of London before the king arrived at Westminster with approximately 400 men to enforce the arrests. When Charles personally entered the Commons to demand the members, the Speaker of the House, William Lenthall, famously refused to reveal their whereabouts, asserting that he had no eyes to see or tongue to speak in that place except as the House directed him.123

This dramatic breach of parliamentary privilege backfired significantly. By failing to secure his objective, Charles lost the confidence of many moderate members of Parliament, further deepening the political crisis that led to the English Civil Wars.12