To whom does "the dowry" belong if the engagement is broken off by the fiancé after he disappeared, and the fiancée requested its annulment?

The default ruling is the prohibition of retracting a gift or a donation. An exception to this is a donation where the donor desires a return; in this case, they are permitted to retract it if they do not receive the intended return.

Regarding what a suitor presents to his fiancée before the marriage contract: 1. If it is part of the Mahr (dowry) (such as the "shabka" (jewelry) in some countries): The shabka returns to the suitor upon the dissolution of the engagement, regardless of whether the dissolution was initiated by him or her; this is because the Mahr is not due except upon the marriage contract. 2. If it is a gift: The preponderant opinion: If the dissolution is initiated by the suitor, he is not entitled to retract his gifts. If the dissolution is initiated by the fiancée, he has the right to demand their return; this is because it is a gift intended for a return (marriage). Other opinions: The Hanafis, Malikis (another opinion), and Shafi'is hold that the suitor may reclaim his gift if it remains in its original state, regardless of the reason for the dissolution.