he Muslims were tolerant towards the Christians and Jews as the Koran considered them to be People of the Book, just like the Muslims themselves. Christians and Jews were granted freedom of worship but were liable for additional taxes as they belonged to the category of dhimml, 'infidel'. Only in special cases could they pursue a military or administrative career. In addition to the standard poll-tax, Christians were also liable for the children's levy, paidomazoma, whereby their children could be recruited and trained up for political and military high office. Christians, from the mid- 16th century, constituted the second largest population group in the Empire. The Patriarchate of Constantinople, who was the head of the Christian millet, had religious and legal jurisdiction over it. From the 18th century Christians, and especially some of the most prosperous among them, enjoyed political and economic progress and became involved in tax collection, trade and the administration of areas such as the Danubian Principalities. The Patriarchate of Constantinople provided a common focus for all the Empire's Christians until the 19th century when the rise of nationalism altered the balance.
