Possession of Jeanne of Albret, then of its son Henri, Mont de Marsan was completely committed in the armed conflicts, that, from 1560, opposed in Catholic and reformed Gascognes and was transformed strong thus in place.
Past to the hands of the reformed in 1561, the city was taken by Montluc in 1569 then reconquered by Henri of Navarre in 1577, to iron to the Catholics in 1580 and, 3 years later, to come back to the Protestant. Since the first fights, the outskirts were, one suspects it, destroyed.
It was also the fate of the convent of the Clarisseses situated since the XIIIème century, to a few hundreds of meters of the Door of Roquefort. Fired a 1st times in 1561 by a Protestant captain who feared that it didn't act as strong for a hostile party, it was shaved in 1577.
The Pincers: a walled bastion constructs in the XVIème century by Henri of Navarre
It is at the end of the XVIème century - enters 1578 and 1586 - that Henri of Navarre would have made undertake on the site of the convent of the Clarisseses, more to the south, on a former field of fair, the construction of 2 walled bastions: the Pincers, situated forward of the ditches bordering the oriental defensive wall of the city.
If several documents note the Pincers, it is especially thanks to the drawing of J. of Weert that one can realize of the importance of these fortifications that modified the oriental surroundings of the city considerably and delayed, without a no doubt, all new extension in this direction.
The 2 bastions framed the path of Roquefort that penetrated in the city by the door of the same name, situated in the axis of the present Big-street. But, on the occasion of their construction, one conducted a resumption of the defensive wall of the city and a re-calibration of the ditch that were endowed with a contrescarpe, as well as one can see it again today. The defensive wall was, besides, prolonged until a walled mill established in border of the Midou.
it seems, on the other hand, that on the occasion of the construction of the north bastion, one suppressed a former path that bordered the ditch to the right of the castle of Nolibos and that succeeded to a bridge on the Twelve named of "god's may", of which it remains again the traces of foundation on the right strand of the river. On the occasion of all its works, one would have, finally, established of the dams on the Twelve and the Midou in order to put in water the systems of the ditches of the city and pincers.
A progressive demolition of the fortifications in the XVIIème century. However, a short time after the completion of these fortifications began a long period, since it lasted until the XIXème century, during which Mont de Marsan lost little by little its castles, its towers, its doors and its defensive walls.
The times had indeed, changed and the military adornment of the city henceforth useless against an enemy coming from the outside could become dangerous in case of revolt inside Kingdom. Since 1622, Louis XIII ordered for these motives the demolition of the castle of Nolibos, which must immediately begin, since in 1677, he is made allusion in the former defensive walls of the castle. But, in 1746, one knocked a tower again down.
It is probably before this date that were shaved the pincers also. Finally, in 1777, was granted the authorization to demolish the 6 doors of the city of which the one of the bridge because of the dangers that their state made run, but especially because of the hindrance of some among them brought to the circulation.
It is to the same time and for the same motives that one thought about knocking what of the Castle-old remained down, but it seems that works not having taken place that in 1810. The demolition of the castle of Nolibos, the one of the pincers and protes and even of the Castle-old, in a 1st time, had for consequence to air the access and the crossing of the city: Nolibos became indeed, a walk, the pincers in particular the big was transformed in place, as besides the Castle-old.
One can connect to these works of édilité the restoration or the construction of buildings as the hospital rebuilds in the oriental part of the district of the Borough by Mgr Bazin of Bezons, between 1696 and 1698, no far from an older establishment, attested in 1452, but in the walls; the reconstruction of the Bridge on the Midou, in 1630, and probably also the restoration of the one of the Twelve; the planning of holds on the sides of the Midouze and the construction of fountains of which most important was the one situated in the district of the Borough no far from the bridge of the Midou.
In the XVIIIème century, 4 convents existed at Mont de Marsan. It is also in the XVIIème century that several convents got settled, either in the city is in the Borough: hunted definitely of their convent out the walls in 1577, the Clarisseses started with buying 3 houses between the Gran-street and the Rue Maubec - they were sheltered there already in 1561 - made then there raise a new convent whose construction was finished, in 1690. The Ursulineses got settled in 1638 unless 100m of there, of the same side of the Big-street; finally, in 1656, the Barnabiteses called by mayor Charles of Lobit and the jurats made the Borough, behind the Big Fountain, to the angle of the Rue du Bourg and the one of the Mirail, build a vast college. However, one century after the castles and the defensive walls, the convents were, to their tower, vowed to the pick of the demolition workers. It was some thus of the one of the Cordelierses whose gardens had been divided before the revolution.
Sold to this time, one drew on its site the Rue des Cordeliers: it doesn't remain any anymore today that the chapel vowed to profane uses. On the site of the convent of the Ursulineses, one opened under the 1st Empire the Rue Duplantier of the name of the second prefect of the Moors: on one hand, one constructed the state police and the jail, of the other the palace of justice. Finally, the site of the convent of the Clarisseses was reserved for the construction of the prefecture that took place between 1811 and 1820.
