I'm searching for details of my g-g-grandfather, Christian Feldmann born Köln 1824. He was Secretary to the German Hospital in London from 1860 to his death in 1894. I have no date or month of birth or details of his parents except that his father is shown on his marriage certificate (London, 7 August 1850) as Hermann Feldmann, occupation - brewer.
Any information or hints on how to trace his German origins in the Cologne area would be much appreciated.