Madonna and Child with Sts Matthew and Nicholas

In 1328 a Florentine friar named Niccolo dei Mazinghi paid for this little folding altarpiece, and along the bottom edge he had the reason spelled out in Latin: he ordered it for the good of the souls of his mother and his brothers, all of them already dead. The same line carries a signature, Bernardus de Florentia painted me, and it is the earliest work Bernardo Daddi both dated and signed that has come down to us. The Virgin and Child sit at the centre, Saint Matthew holding his Gospel on the left, Saint Nicholas in a bishop's mitre on the right. Because it was meant for prayer at close range, the two wings fold shut over the middle. For centuries it stood in the convent of Ognissanti here in Florence, reaching the Uffizi only in 1871.