I found a near exact likeness of this sweet blue and white mustard pot dating it to right around 1800, English. The lid shows a little damage and old repair, but it's always a bit of a miracle to find a little pot with its lid still on it some 200+ years later! I love the blue stripe around the middle, with excellent painterly bleeding to the blue and a dip on one side,  reminding me a bit of "seaweed" decoration on old yellowware and mochaware. Makes me want to host a proper lunch in order to serve mustard in it, but it's also the time of year when I want to fill every vessel around with freshly plucked flowers, and I think how perfect this would be filled with violets or lily of the valley, the lid set safely aside. 

3 3/4 t with lid on x 3 1/2 across at handle x 2 1/2 d. x 2” across lip.  Good overall condition for its age, with a couple of very very fine surface hairlines around the lip of the the vessel and some yellowing around the rim of the lid, I believe product of an old repair. See detail photos.