I M Chaney Antique Furniture has dated this piece to the 17th Century.
Measuring
Height 3.5 cms
Width 13 cms
Depth 5.5 cms
Condition
One corner has an old soldered repair which is not perfect but not really visible either

There is an almost identical one at British museum and this is what they say about it ;
A Protestant tobacco box: the smell of the Reformation?
This brass tobacco box dating from the late seventeenth or eighteenth century attests to the fusion of this popular cultural habit with evolving myths about the Protestant Reformation. It bears on its base and lid images of the reformers Martin Luther and John Calvin, each carrying an open book. The swan above Luther alludes to the famous prophecy associated with his predecessor Jan Hus, the Bohemian heretic put to death in 1415, who is said to have predicted that though he was roasted as a goose, in a hundred years’ time a swan would sing. The verses below celebrate Luther as the light that revealed the holy Gospel to everyone. Mimicking an iconography familiar from the printed portraits that proliferated all over Europe, this domestic object demonstrates how these figures became convenient visual short-hands for the religious revolution they were credited with inaugurating. It brings together two men who were less allies than antagonists and who clashed on critical theological issues, reducing them to heroic figureheads and generic symbols. Suggestive of the role of the senses in the culture of remembering, the box raises an intriguing question: might the smell of tobacco have served to evoke the memory of the Reformation itself?
Taken from the British museum description.
I M Chaney Antique Furniture has dated this piece to the 17th Century.
You can view the stock and full dealer information on the I M Chaney Antique Furniture Profile Page