This is one of five panels (A76 to A80-1919) from a casket or an altarpiece made at the workshop of Baldassare Embriachi (Ubriachi) in about 1390-1410 in North Italy, Florence or Venice. This panel depicts the plague of flies (Exodus, VIII, 21-31). The remaining plaques illustrate another three of the ten biblical plagues of Egypt and the fifth depicts a shepherd in a landscape.
Embriachi plaques depicting the Old Testament are rare, and only one casket with Old Testament scenes is known.

The Embriachi workshop was a north Italian family of entrepreneurs and carvers. The precise location of the workshop is unknown, except that it originated in Florence in around probably the 1370s.
Baldassare Embriachi, a member of a Florentine noble family, and the Florentine literary circles, during his career acted as both merchant and diplomat. He was therefore rather the financial means behind the bone-carving workshop that bears his name, rather than its leading artist. By 1395, political and financial circumstances had forced him to transfer to Venice. The suggested time range of activity for the workshop differs, from the tightest being 1390-1405, to a wider span of 1370s until at least 1416, but certainly no later than 1433.

They employed local workers specialising in 'certosina' (inlay of stained woods, bone and horn), and the workshop produced items carved in bone (usually horse or ox) with wood and bone marquetry.
As well as altarpieces, the workshop also made caskets as bridal gifts to hold jewels or documents, and these were often decorated with scenes from mythology.