Murad has distributed most of his conquests to members of the Kapikulu force, occasionally as timars but more often as tax farms (iltizams), so that the treasury can obtain the money it needs to maintain the Janissary army entirely on a salaried basis.

In addition, in order to man the new force, Murad has developed the devsirme system by which promising Christian youths are drafted from the Balkan provinces for conversion to Islam and life service to the sultan.

Subject to strict rules, including celibacy, they are organized into three unequal divisions (cemaat, bölükhalki, segban) and commanded by an aga.

By 1425, Murad has eliminated his rivals, has reestablished Ottoman rule over the Turkmen principalities of western Anatolia, and has once again forced Constantinople to pay tribute.

He now turns his attention to the Balkans.