mutinied under the direction of one of Constantine's I sons, Constantius II ( http://en.wikipedia.org/wiki/Constantius_II ), and killed much of Constantine's I family.  Constantine's I three surviving sons, Constans (http://en.wikipedia.org/wiki/Constans), Constantine II (http://en.wikipedia.org/wiki/Constantine_II_(emperor) ) and Constantius II  divided the empire into three parts as he (Constantine I) wished, but then they began feuding over the empire.  Constantine II,