In some parts of China, beginning in the Southern Tang kingdom in Nanjing (937-975), the custom of foot binding was associated with upper class women who were worthy of a life of leisure, and husbands who could afford to spare them the necessity of work (which would require the ability to be mobile and spend the day on their feet). Because of this belief, parents hoping to ensure a good marriage for their daughters would begin binding their feet from about the age of seven years to achieve the ideal appearance. The tinier the feet, the better the social rank of a future husband.