Mesazon

[1] The term's origins lie in the 10th century, when senior ministers were sometimes referred to as the mesiteuontes (μεσιτεύοντες), i.e. 'mediators' between the emperor and his subjects (cf.

The title first became official in the mid-11th century, when it was conferred on Constantine Leichoudes, the future ecumenical patriarch of Constantinople.

[2] In the Komnenian period, it was awarded to senior government officials who functioned as de facto prime ministers, such as the epi tou kanikleiou and the logothetes ton sekreton, but had not yet acquired a permanent and specific function, nor the power that would characterize it in later years.

[2][3] Rather, it was a title bestowed on the principal imperial secretary of the moment, who acted precisely as an "intermediary" between the emperor and other officials.

[2] This arrangement was inherited by the restored Palaiologan-era Empire and continued in use until the Fall of Constantinople in May 1453.