England declared war on France, supporting Philip II, leading to the loss of Calais.
On June 7, 1557, Mary I, alongside her husband Philip II, declared war on France, dragging England into the prevailing Italian War of 1551-1559. This declaration was a strategic response to French provocations and Habsburg alliances, demonstrating Mary's substantial support for her husband's continental ambitions. Unfortunately, this conflict ultimately led to the fateful loss of Calais, England's last French territory, marking a symbolic end to England's tenure as a continental power and significantly impacting national prestige during and beyond Mary's reign.