Liz, Fascinating story. I won't put all the details up on the List for privacy reasons. It would seem from the information you have posted and from that here: http://freepages.genealogy.rootsweb.ancestry.com/~cmtilbury/india_wm_h_t_rsm .html that your great-grandfather could indeed have been William Henry Tilbury of the Berkshire Regiment. He and his wife Caroline (married 1920 in England) did indeed have a son in England (1922), who in turn married and had another son in England (1958). This great-grandson of WHT may also have married and had issue, but there are a number of people with the same name and I cannot tell which marriage, if any, is his - you might have to purchase a few marriage certificates from the GRO to get the right marriage and then you could see if there were any children. If you could locate this great-grandson of WHT (and there are ways of trying), I think an autosomal DNA test for both of you has a good chance of showing whether you share the same great-grandfather. No other DNA test will help you in your particular case. Of course it is not an easy thing to ask someone to undergo a DNA test, and there is no guarantee that even if you did make contact that WHT's great-grandson would want to do so. Of course if you can get a reply from Lahore then they may be able to tell you who deposited your grandmother in the Convent, enabling you to by-pass the detective work! I think that you can look up the GRO BMDs on ancestry without having a subscription, but if that is not the case then I can easily send you the details off-list. I emphasis that I am not connected to the family in any way.