Thankyou all for the feedback. It appears that my theory is at least possible. I don't really have a possible first son's birth or death but was just checking that it was a possiblility. I'm looking for parents for my Walter Ritchie (b.circa 1796) and,with no obvious standout possibilities,began to look at other scenarios. I found possible parents who would fill the criteria as far as the other children of Walter & Martha were concerned providing I made the assumption that a first son had been born and then,conveniently,died. I know,it's the old long bow again and I've changed the string more than once already but at least I'm still aiming at the same target. Incidentally how do illegitimate children figure in this naming scheme? e.g.If Martha had a child before she married Walter,and to a different father, is it still child number one? or only as far as Martha is concerned? Sorry about that last query - I know I'm pushing my luck. Ian Ritchie