Isaiah

Barthélemy d'Eyck's Isaiah is linked to the same Aix Annunciation Triptych programme as his Mary Magdalene, where Old Testament prophets on the outer wings created the typological frame for the Annunciation within. Isaiah was the pre-eminent prophetic authority for the Incarnation — 'Behold, a virgin shall conceive' — and his inclusion on the Aix altarpiece wings was doctrinally precise. D'Eyck renders him as a monumental, serious figure whose gravitas reflects the French court's taste for a Flemish illusionism inflected with literary seriousness.

The prophet is depicted with volumetric solidity unusual in French painting before Fouquet, achieved through the Flemish oil technique of layered glazes. The scroll or book Isaiah carries shows careful attention to the material quality of parchment. Drapery folds are rendered with architectural conviction — large planes of colour with deep shadows — rather than the decorative linearity of the Gothic tradition.