Part of the preface that martyr Osman Saleh Sabbe, wrote to the Arabic Translation of the book, “My Mission to Abyssinia 1887” by Gerald H. Portal:
“The book is a historical account of a voyage to Abyssinia intended to distribute the Turkish heritage between Italy (that came to the region encouraged by Britain in order to face the French influence in the red sea), and Abyssinia, which the British found to be a prospective ally useful in suppressing the Mahdi revolution in the Sudan.
In order to understand the circumstances of the voyage narrated by Portal, the envoy - a British Council in Egypt then - we have to refer to an earlier voyage led by another British envoy namely Admiral Hewett in 1884. Admiral Hewett met Emperor Johannes and reached an agreement whereby Britain ceded to Abyssinia, the possessions of the Ottoman Empire in the Red Sea region that was under Khedive proxy administration (for the British) , including the garrisons in the Eritrean highlands , Keren plateau, as well as Massawa port and environs. This was in consideration of the participation of Abyssinia in the war against the Mahdist government in the Sudan. Britain took such rights by virtue of its dominance in the Egyptian state of affairs after the failure of the Orabi revolution in 1882.
The forces of the Egyptian Khedive and its allies of Eritrean leaders was disgracefully defeated by the forces of Emperor Yohannes in Guraa and Qandit in the Eritrean highlands in 1875 and 1876. The Khedive was forced under the mediation of Britain to withdraw its forces from that region leaving behind all arms and ammunition for the Ethiopian Army. They also paid a ransom of 20 millon Terezza Riyals to free prince Ismail Pash, who a captive of Yohannes forces, then.
Britain did not fulfill its promises to Yohannes, yet it opted to encourage Italy to occupy the Eritrean coast because Abyssinia- as Portal indicated, was not in a position to defend those positions against any ship(sent by any European power). Britain was preoccupied in restricting the French influence emanating from Djibouti.