English: The Danube and Black Sea Railway Kustendje Harbour Company Limited, DBSR in short, was a British company active in Romania that established harbours at Constanta (Kustendje, for Austrian Lloyd) and Crenavoda (Czernawoda for Danube Steam Navigation Company) and built a railway between them which crossed the Dobrogea so that boats did not need to make the dangerous crossing of the Danube Delta.

In 1865 the DBSR issued a single stamp for use on letters carried on the railway between the two ports. This stamp is normally found used in combination with the stamps of Austrian Italy. The stamp was printed by Kaiser in Vienna in black on shades of blue-green paper with punched out perforation giving 9, 11, 9, 12 points at top, right, bottom and left of stamp respectively.