Portrait of Constantine XI Palaeologus, half-length turned to the left, bearded, looking upwards to the left, hands raised, wearing turban; illustration from <a href="https://en.wikipedia.org/wiki/Andr%C3%A9_Thevet" class="extiw" title="en:André Thevet">André Thevet</a>'s 'Les vrais pourtraits et vies des hommes illustres' (Paris, 1584), page 291.
<br>Engraving, letterpress below and on verso
<a rel="nofollow" class="external free" href="https://www.britishmuseum.org/collection/object/P_1879-1213-201">https://www.britishmuseum.org/collection/object/P_1879-1213-201</a>