In the 19th century the colonial powers from Europe began noting numerous forced conversions and massacres, usually generated by Shi'a clergy. Two major blood-libel conspiracies had taken place during this period, one in Shiraz and the other in Tabriz. In 1830, a blood-libel had wiped out the Jewish population of Tabriz; a power struggle over influence between Jewish and Christian minorities led the Armenians to kidnap and murder a Muslim child from a prominent family, delivering the body to the chief secretary claiming that the Jews had murdered and drank the blood of the child for Passover. A document recorded after the incident states that the Jews faced two options, conversion to Islam or death. Amidst the chaos, Jews had converted, but most refused to convert to Islam – described within the document was a boy of age 16 named Yahyia who refused to convert to Islam, he was subsequently killed. The same year saw a forcible conversion of the Jews of Shiraz over a similar incident. In addition to the Allahdad incident mentioned above in 1839. European travellers reported that the Jews of Tabriz and Shiraz continued to practice Judaism in secret despite a fear of further persecutions. Famous Iranian-Jewish teachers such as Mullah Daoud Chadi continued to teach and preach Judaism, inspiring Jews throughout the nation. Jews of Barforush, Mazandaran were forcibly converted in 1866. When the French and British ambassadors intervened to allow them to practice their traditional religion, a mob killed 18 Jews of Barforush. Perhaps these things happened earlier too, but went unnoticed by the historians.