Early in 1887 four messengers were despatched with letters to Her Majesty the Queen of England, His Majesty the Sultan of Turkey, and His Highness the Khedive. These envoys were permitted to come to Cairo, and to personally deliver their letters; but when they were opened, perused, and found only to contain a summons from the Khalifa to adopt Mahdiism, and submit to him, or the recipients would suffer the same fate as Gordon and Hicks, the messengers were at once sent back without any reply being given to them, and this was considered by Abdullah to be the greatest insult that could have been offered to him. The Dervish advanced-guards continued to creep on towards the Egyptian Frontier, whilst Hassan Khalifa, the nephew of the former Mudir of Berber, occupied the desert wells, and made several incursions on the river to the north and south of Korosko. Mounted on dromedaries, these bold raiders made sudden descents on defenceless villages, carried off quantities of booty, and then disappeared into the desert. At this time the Egyptians had retired to Wadi Halfa, and the Dervishes had occupied Sarras, a little to the south, from whence they constantly harassed the Egyptian outposts. A variety of circumstances, however, occurred to prevent Khalifa Abdullah from carrying out his projects against Egypt. The revolt in Darfur, the Abyssinian war, internal dissensions, all contributed to impede the despatch of troops north. Besides, the Dervish garrison in Dongola had already done much to destroy the well-being and prosperity of the province; they plundered the inhabitants, who, in their turn, became averse to the Dervish occupation; continued warfare had produced a famine; numbers died of small-pox. Bahr el Karrar in 1888 occupied the wells of Haimar and Ongat, and from here was able to annoy the inhabitants on the Nile between Assuan and Korosko. He raided the village of Kalabsheh, some fifty miles south of Assuan, killed the Egyptian police guards, and carried off their officer a captive to Omdurman. All this time there was a great deal of talk in the capital about the conquest of Egypt, but we never received any very decisive news. The captured officer was paraded through the streets in triumph, and was then brought before the Khalifa, who received him kindly, and questioned him very fully about Egypt; but he quite understood what sort of replies to make to the Khalifa's questions, and only told him what he knew would please; so he was well treated, set at liberty, and now lives in Omdurman. From time to time the Khalifa despatched reinforcements to Dongola which never returned, and this was the reason of the main road leading north out of Omdurman being called "Darb Esh Shuhada" ("The Martyrs' Road ").