I did a little research on Monpazier's foundation on the Net. The following is culled from that study.
The period between the end of the 10th and the end of the 13th centuries was marked by a population explosion in the whole of Europe. The population in the south-west region was governed by a feudal system, the two essential authorities being the Duke of Aquitaine and the Counts of Toulouse.
It was in the second half of the twelfth century that Edward I, King of England, orderd the construction of the Bastide of Monpzier to fortify border positions. In 1284, the land was ceded to the King to build Monpazier.
The origin of the name could come from Montpaciarus, or Mountain of Peace, or Monti Paserii, or Mountain by which one passes through. It has also been written Montpazier.
There are about 300 Bastides, or New Towns, of which Monpazier is a perfectly preserved example.
They were generally built on empty sites or cleared forest; the whole area in the middle ages was forested with hardly any routes/lanes of communication.