In November 1879, a young Roman Catholic woman was kidnapped by a Muslim male of the Sarayra family, and her relatives demanded her return. The Majalis, the leading Muslim notable family in the region, sided with the Catholics, and the woman was released to the Majalis, who in turn handed her over to local Catholic clergy.
Unfortunately for the Catholic clergy, simply returning her to her family proved not to be an option, as the people of Karak insisted she be killed to redeem the family's honor, in what is now known as an "honor killing." The priests, therefore, Fr. Alexandro Macagno and Fr. Paolo Bandoli, smuggled her to Jerusalem and on to Nablus. Her brother, frustrated in his determination to murder her, turned instead on the Sarayra, and killed a number of them at Wadi Hasa near the city.
This, in turn, led to tribal tensions between the Sarayra and the Roman Catholic tribe of 'Uzayzat, and the Catholic clergy decided the best thing to do would be to simply have their flock leave the area. Accompanied by three 'Uzayzat shaykhs, Fr. Bandoli surveyed central Jordan, and together they decided Madaba was the best place to settle.
The determination to let the Christians have Madaba was made by none other than Midhat Pasha, a reformist statesman who turns up all over the mid-19th century Ottoman Empire, and at this time was governor of Damascus. The settlement was opposed by Sattam Fayiz of the Bani Sakhr tribe, which claimed Madaba as part of their domain and didn't want to lose it, while potentially forming an alliance with the Majalis of Karak. Midhat Pasha, however, ruled against the Bani Sakhr as part of his overarching program to get the tribal authorities to submit to the Ottoman administration, in this case by registering land and paying taxes on it. They hadn't done that, so in the eyes of the state the land was vacant and the 'Uzayzat could claim it.
One other side note is that Fr. Bandoli, who led the migration from Karak to resettle Madaba, was himself and interesting figure who tried to take on the role of Bedouin shaykh in Madaba and ultimately ended his life as a book peddler for the Protestant Bible Society in Alexandria, Egypt.