Johann Adam Schall von Bell (1 May 1591 – 15 August 1666) was a German Jesuit, astronomer and instrument-maker. He spent most of his life as a missionary in China (where he is remembered as "Tang Ruowang") and became an adviser to the Shunzhi Emperor of the Qing dynasty. Life Schall von Bell was born to noble parents in Cologne or nearby Lüftelberg (today part of Meckenheim) in the Holy Roman Empire. After he graduated from the Jesuit Gymnasium in Cologne he moved to Rome and studied subjects such as mathematics and astronomy at the Collegium Germanicum. In 1611 he joined the Society of Jesus and continued his education at the Gregorianum. In 1618 he left for China on a Portuguese ship with a group of missionaries under the lead of Nicolas Trigault. The next year the group reached the Portuguese trading port of Macau where Schall von Bell spent some time learning Chinese. He started missionary work inside China in 1622, but allegedly his success was limited. He participated in the defence of Macau from a Dutch invasion in the same year, and personally took a Dutch captain prisoner from that victorious battle. Schall von Bell and Giacomo Rho were sent to Beijing in 1630 to continue the work of the deceased Johann Schreck on a reform of the Chinese calendar. With Xu Guangqi, he participated in modifying the Chinese calendar and compiling what is known as the Chongzhen calendar. Named after the Chongzhen Emperor, the last emperor of the Ming dynasty, the modified calendar provided more accurate predictions of eclipses of the sun and the moon. Upon Xu's passing, he held the requiem in his honor and oversaw the process of shipping the body back to his relatives in Shanghai. The Ming obtained the services of Father von Bell’s foundry in Beijing, which is said to have produced some five hundred cannon. After the Ming-Qing Transition in 1644, Schall von Bell gained access to the newly installed Shunzhi Emperor and became one of his trusted counsellors. He was made a mandarin and held an important post in connection with the mathematical school: Director of the Imperial Observatory and the Tribunal of Mathematics. His position enabled him to procure from the emperor permission for the Jesuits to build churches and to preach throughout the country. Thus Schall von Bell is indirectly credited with 500,000 Chinese that are said to