In Roman law the appointment of a substitute heir (substitutus), so as to avoid the danger that a will might become ineffective through the potential absence of the heir appointed by it (as a consequence of prior death or refusal; Succession, laws of III. D.). Instances of the modern-day persistence of substitutio vulgaris ('common substitution') are 'gemeine Substitutio' (§ 604 Austrian ABGB) and 'Ersatzerbeinsetzung' (§ 2096 German BGB).
In the case of dependent minors of either sex, a Roman testator could prepare a second will settling the su…