I, amongst others, am researching the family name.So far we are back to 1781 with Joanna daneelwich born in Venice(Italy),
captured aboard a French Frigate in 1794(Sybille) by H.M.S. Romney.
As Joanna could not read or write, the name was written in 1799 as it was said to the church recorder. I believe the name may have come from the Baltic states, or more likely, the Polish name Danilowicz which is said in the same way.
Any information (or amendments!) you can give me, or if you are a Demellweek and are not on my tree, then please drop me a line.