« Reply #10 on: Sunday 15 March 15 07:14 GMT (UK) »
Your ancestor must have been a citizen of the Ottoman Empire, or at least registered as such with the British authorities. That would have been the reason he was incarcerated.
Have you checked Kew, or elsewhere, to see if records of "aliens" residing in England still exist?
I am Australian, from all the lands I come (my ancestors, at least!)
Pine/Pyne, Dowdeswell, Kempster, Sando/Sandoe/Sandow, Nancarrow, Hounslow, Youatt, Richardson, Jarmyn, Oxlade, Coad, Kelsey, Crampton, Lindner, Pittaway, and too many others to name.
Devon, Dorset, Gloucs, Cornwall, Warwickshire, Bucks, Oxfordshire, Wilts, Germany, Sweden, and of course London, to name a few.