This article seeks to identify the distinctive features of costume-inflected portraiture of Russian tsarevnas in the age of Peter I within the broader context of European art. The characteristics of the costumed portrait as a distinct type in Russia are examined through comparison with portrait images of princesses from European dynasties. Whereas portraits of Russian tsarevnas have not previously been treated as a separate category, this study proposes to consider them as a particular variety of the female portrait in the early modern period. The article focuses on the allegorical personae most frequently encountered in portraits of tsarevnas and princesses, above all Flora and Diana. The specific character of their Russian articulation was shaped in large measure by the defining features of Petrine painting, with its urgent imperative to assimilate the possibilities of early modern art. The logic of this development determined both the reliance on an already established Western European artistic tradition, mediated by foreign masters such as Louis Caravaque, and the relative restraint of the range of classical personae in comparison with other European national schools. The Western European tradition is represented here by examples drawn from French, English, and Italian painting. A comparative iconographic analysis, informed by the historical and cultural contexts in which these portraits were produced, makes it possible to discern new layers of meaning within them. Costumed portraits fulfilled a crucial representational function, situating royal women within an elevated mythic realm shared across European artistic culture, a framework through which their virtues, chastity, and the natural beauty refined by court culture could be articulated. Tsarevnas and princesses were conventionally cast both as patrons of culture and as desirable brides whose advantageous dynastic marriages might exert considerable influence on international relations. A central task for artists was to maintain an equilibrium between the sitter's individual features and the broadly legible allegorical persona, rooted in European culture, that she was made to embody. Accessories and attributes played a particularly significant role in such images, for they enabled viewers to identify the figure whom the sitter personified.