In the history of the Christian church missionary activity is seen to be intermittent, and an age of apostolic fervour may be succeeded by a period of apathy and indifference, or persecution and forced conversion may take the place of the preaching of the Word; so likewise does the propaganda of Islam in various epochs of Muhammadan history ebb and flow. But since the zeal of proselytising is a distinct feature of either faith, its missionary history may fittingly be singled out as a separate branch of study, not as excluding other manifestations of the religious life but as concentrating attention on an aspect of it that has special characteristics of its own. Thus the annals of propaganda and persecution may be studied apart from one another, whether in the history of the Christian or the Muslim church, though in both they may be at times commingled. For just as the Christian faith has not always been propagated by the methods adopted in Viken (the southern part of Norway) by King Olaf Trygvesson, who either slew those who refused to accept Christianity, or cut off their hands or feet, or drove them into banishment, and in this manner spread the Christian faith throughout the whole of Viken, [13]—and just as the advice of St. Louis has not been made a principle of Christian missionary work,—“When a layman hears the Christian law ill spoken of, he should not defend that law save with his sword, which he should thrust into the infidel’s belly, as far as it will go,” [14]—so there have been Muslim missionaries who have not been guided in their propagandist methods by the savage utterance of Marwān, the last of the ʻUmayyad caliphs: “Whosoever among the people of Egypt does not enter into my religion and pray as I pray and follow my tenets, I will slay and crucify him.” [15] Nor are al-Mutawakkil, al-Ḥākim and Tīpū Sulṭān to be looked upon as typical missionaries of Islam to the exclusion of such preachers as Mawlānā Ibrāhīm, the apostle of Java, Khwājah Muʻīn al-Dīn Chishtī in India and countless others who won converts to the Muslim faith by peaceful means alone.