Antique 19th Century North African Sudanese Islamic Mahdist Dervish Arm Dagger

A good quality antique, late 19th century North African, Sudanese Islamic, Mahdist Dervish, arm dagger with scabbard, from the Mahdist War period (a revolutionary insurrection against the British colonial rule in Sudan, which took place in 1881-1899). 
It was called the Mahdist War since the Sudanese leader Muhammad Ahmad bin Abd Allah (محمد أحمد ابن عبد الله‎) 1848-85 proclaimed himself " Mahdi of Islam" (the "Guided One").
Details: a leather-wrapped hilt in a distinctive form, comprising a slim grip adorned with finely braided leather straps and surmounted by the triangular flat iron pommel. Straight, double-edged tapering hand-forged steel blade cut with fullers with a medial ridge and beveled edges.
Complete with its tooled leather scabbard with triple ridged throat bulbous tip and braided leather arm loop.
These daggers were carried on the upper left arm for rapid access with the right hand, hidden beneath clothing.
CONDITION: Excellent example for the period in fine preservation with fine patina, blade slightly pitted.
MEASUREMENTS:
Overall length: 30 cm (11.81 inches)
Overall length without the scabbard: 29.5 cm (11.61 inches)