In the Middle Ages people who rented messuages did so under a system whereby you paid a sum of money on taking up the messuage then a smaller sum each year, known as your fine. You rented for a period of three named lives. Therefore, if you were called John, you might call two children John, in hope that at least one would survive and himself have a son John. By the time of the English Civil War it became much less common to have two live children with the same name. claytonbradley