 By the end of the 16th century, knights were becoming obsolete as countries started creating their own professional armies that were quicker to train, cheaper and easier to mobilize.The advancement of high-powered firearms eradicated the use of plate armour, as the time it took to train soldiers with guns was much less compared to that of the knight.The cost of equipment was also significantly lower, and guns had a reasonable chance to easily penetrate a knight's armour.