Harleian ms. 3244, folios 27-28, showing an allegorical knight preparing to battle the seven deadly sins with the "Scutum Fidei" diagram of the Trinity as his shield.  
<p>This is part of a ca. 1255-1265 illustration to the <i>Summa Vitiorum</i> or "Treatise on the Vices" by <a href="https://en.wikipedia.org/wiki/William_Peraldus" class="extiw" title="en:William Peraldus">William Peraldus</a>.  For detailed discussion of the manuscript, see the article "An Illustrated Fragment of Peraldus's <i>Summa</i> of Vice: Harleian MS 3244" by Michael Evans in <i>Journal of the Warburg and Courtauld Institutes</i>, vol. 45 (1982), pp. 14-68.  
</p>
<dl><dd>"The picture is exceptional for several reasons: there is no comparable representation of the vices; depictions of the <i>miles christianus</i> in emblematic armour are extremely rare before the Reformation; the juxtaposition of the various elements is unprecedented in medieval figurative art; and no other illustrated MS of Peraldus is recorded." (Evans p. 14)</dd></dl>
For the device on the knight's shield, see image description page <a href="//commons.wikimedia.org/wiki/File:Trinity_knight_shield.jpg" title="File:Trinity knight shield.jpg">File:Trinity knight shield.jpg</a>.
anonymous illustration of Guilelmus Peraldus, <i>Summa de virtutibus et vitiis</i>
mid 13th century (after c. 1236; c. 1255-1265)
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