Louvre was build by Philippe-August as a fortress in XIII century. At that time it wasn't a royal residence, as the king preferred to live on the Cité island. Royal treasury and archives were situated there. In XIV century Karl V made the fortress more comfortable and turned it into royal residence. He also ordered to build a library, since then he was called "Wise". But after his death Louvre was not used as royal residence for a long time. In 1564 Louvre was rebuild in accordance with renaissance style. In order to do that, old fortress was demolished and on its base a new palace appeared. Since then all the Kings of France but Louis XV continued to enlarge the palace and Louvre, as we see it today looks so since 1871.
Although Louvre was situated in the capital and considered to be the royal palace, Louis didn't like it and always tried to move from it. Louvre was situated in the middle of that dirty loud Paris, if was surrounded by beggars and prostitutes, it was half-fortress and Louis had unpleasant associations because of Fronde. On the other hand he restored it and turned that half-fortress into a palace. He also tried to make Paris a livable town.