When the Portuguese reached China in the early 16th century, they were unimpressed with Chinese firearms compared with their own. With the progression of the earliest European arquebus to the matchlock and the wheellock, and the advent of the flintlock musket of the 17th century, they surpassed the level of earlier Chinese firearms. Illustrations of Ottoman and European riflemen with detailed illustrations of their weapons appeared in Zhao Shizhen's book "Shenqipu" of 1598, and Ottoman and European firearms were held in great esteem. However, by the 17th century Đại Việt had also been manufacturing muskets of their own, which the Ming considered to be superior to both European and Ottoman firearms, including Japanese imports as well. Vietnamese firearms were copied and disseminated throughout China in quick order.