This image featured on both the 7p and 9p Christmas stamps in Ireland in 1976. It was painted by Lorenzo Monaco, real name Piero di Giovanni, also known – rather fabulously – as Lorenzo The Monk.
Lorenzo was born in Siena in 1370 and apprenticed as an artist in Florence. At the age of 20 he became a monk, which I guess makes the nickname a bit more descriptive than atmospheric.
His work was colourful and focused on sacred imagery. He often painted onto panels that had been gilded (covered in gold leaf) so you get this very opulent impression of glorification of sacred scenes. He lived until around 1425, a time when other painters were starting to transform painting through the use of geometric perspective.
The Nativity shown here was painted in 1414.