It is an effigial tomb, meaning it bears carved, recumbent figures of the deceased lying in full relief on top, and this one is unusually detailed for a monument that has spent a good portion of its existence displaced from the church it was made for.

The tomb is attributed to the Purcell family and dated to somewhere between 1500 and 1520, placing it in the final decades of medieval Dublin. It was not always at St Werburgh's. It originated in the church of St Mary del Dam, a medieval Dublin parish church that no longer survives, and was moved to its current location sometime in the late sixteenth or early seventeenth century, most likely after St Mary del Dam fell out of use. The male figure is carved in full plate armour of late Gothic type, the articulated metal suit that would have been fashionable among the Anglo-Norman and Anglo-Irish nobility of the period. Beside him, the female figure wears a pleated gown cinched at the waist by a belt decorated with rosettes. What makes the tomb particularly remarkable is not the effigies themselves but the three carved side panels surrounding them. The east end shows an archbishop, an enthroned Madonna and Child, an abbess, and an ecclesiastic. The north panel is crowded with saints: Apollonia, a representation of the Holy Trinity, St John the Baptist, St John, and St Paul, alongside four figures who remain unidentified. The west panel features an archbishop, St Francis, St James, and St Peter, though one recess in that panel has been damaged and its subject is now lost. The depth of the iconographic programme, as this kind of systematic arrangement of religious figures is known, suggests a family of considerable means and piety.

St Werburgh's is an active Church of Ireland parish church and access can be variable, so it is worth checking opening times before visiting. The tomb sits in the porch rather than the main nave, which means it is sometimes visible even when the interior is closed. Look closely at the side panels; the carving is fine enough that individual attributes of each saint, the items they hold or the clothing they wear, can still be made out despite centuries of wear and the occasional patch of damage.