A Vicomte acted as a lieutenant of a Comte if the Comte had his hands full already or if the land in question was owned by the King. Occasionally, the youngest son of a Comte is given the title of Vicomte. The area owned by a Vicomte was usually a part of a county. Normally, a Vicomte would be entrusted with taxation, overseeing justice and take care of the châteaux in the area.
During the time of the Ancien Regime the title of Vicomte was no longer handed out by the King or the Comte but had became a hereditary title.