This research studied the construction technology of various typologies of three-leaf masonry walls in archaeological Islamic buildings in Cairo. It highlighted on the core layer of these walls, and its main structural role, especially in moderate and wide thickness' walls. It studied analytically, using numerical modeling technique that utilizing Finite Element Method; the share of each layer in the three-leaf masonry walls under vertical loads and reached to correlate it with normal stiffness during elastic phase. This paper also studied the development and structural functions of embedded timber ties in masonry walls; in both Egypt and worldwide. It demonstrated the structural behavior and failure mechanisms of the three-leaf masonry walls under vertical loads, using results of both structural analysis work of numerical models (conducted in this paper) and pervious experimental work of latest researches in this field. It studied the use of timber ties in restoration and reinforcing of deficient historic three-leaf masonry walls. Finally, conclusion and recommendations were derived.