And first of all what were the motives that can incite, toward 1133, viscount Pierre of Lobaner to establish a castle and to found a castelnau on the sides of the Midouze?
Such an initiative having to this time anything exceptional, one can be assured of the political character of the foundation and the viscount's will to affirm his authority in this part of his vicomté. Otherwise, in a relatively flat country, the site could only keep the attention, from the moment one wished to build a castle and a walled village. But, if these factors could motivate the viscount's conduct and could guide his choice, the one that was, to our opinion, determining, that was will vicomtale to control the passage of the Midou by the road of the Small Moors. That there was already to this place a passage or that the castelnau attracted the road, no matter.
The construction on the path of Roquefort, to the entry of the city, of a hospital dedicated to Saint-Jacques, the place occupied by the incomes of the toll in the finances vicomtales proves well how once founds, the castelnau had to for a large leaves his flight to his situation on an important way of passage, and it whatever could be otherwise the advantages that the inhabitants withdrew their establishment in his walls.
The planning of a jetty then the construction of a bridge on the Midou, to the very foot of the castle, accompanied or followed of little the foundation of the castelnau, but they nearly dragged way unavoidable the apparition of a borough on the opposite strand. The fact that this bridge is himself open on a real road goose paw could only increase his attractive character. He doesn't seem, however, that the bridge and the road crossroads were the only factors that determined the birth then the flight of the Borough. He agrees, indeed, not to forget that the Midouze was navigable. Although we need the Middle Ages no formal proof, he is likely that, since this time, a port settles on the left strand of the river, downstream the bridge, while several mills were installed in border of the Midou, since 1155.
Under the successive tutelage of the viscounts of Marsan, Bigorre and the Béarn (1256), finally under the one of the counts of Foix, from 1286, the city acquired its autonomy progressively, punished by the growth, in 1273, of a "mayretat" attested some years before by a seal (1259) and by the existence of a" common advice (1266)."
