This is not anonomly.This is just the norm.because the psychological and biological aspects were different and changes over period of time.
Look at this scientific journal
questia.com/PM.qst?a=o&se=gglsc&d=98501236
....since elite women generally married around the age of puberty or even earlier...
..The marriage ceremony itself, which often took place when a girl was twelve years old, and sometimes even earlier...
..While certain biological and even psychological aspects of human de velopment may be universal -- although sociologists, psychologists, and historians debate this -- A study of the lives of elite women in England and France between 1050 and 1300 illustrates this reality...
