Under Childeric's son Clovis I (r. 509–511), the founder of the Merovingian dynasty , the Frankish kingdom expanded and converted to Christianity. The Britons, related to the natives of Britannia – modern-day Great Britain – settled in what is now Brittany .  [G] Other monarchies were established by the Visigothic Kingdom in the Iberian Peninsula , the Suebi in northwestern Iberia, and the Vandal Kingdom in North Africa .  In the sixth century, the Lombards settled in Northern Italy , replacing the Ostrogothic kingdom with a grouping of duchies that occasionally selected a king to rule over them all. By the late sixth century, this arrangement had been replaced by a permanent monarchy, the Kingdom of the Lombards . 
Demography is today widely taught in many universities across the world, attracting students with initial training in social sciences, statistics or health studies. Being at the crossroads of several disciplines such as sociology , economics , epidemiology , geography , anthropology and history , demography offers tools to approach a large range of population issues by combining a more technical quantitative approach that represents the core of the discipline with many other methods borrowed from social or other sciences. Demographic research is conducted in universities, in research institutes as well as in statistical departments and in several international agencies. Population institutions are part of the Cicred (International Committee for Coordination of Demographic Research) network while most individual scientists engaged in demographic research are members of the International Union for the Scientific Study of Population,  or a national association such as the Population Association of America in the United States,  or affiliates of the Federation of Canadian Demographers in Canada.