Before the beginning of the WWII French GHQ noticed (belatedly) that in case of a breakthrough of the front line on our northern border, there was no more
means to defend Paris, as far as the old forts of 1874 being obsolete and no secondary line was completed.
To counter in the urgency in this, it was decided to build a belt of bunker (mainly for antitank purpose) in about fifty km in the North half of the capital
(From Conflans-Sainte-Honorine on the West to La-Ferté-sous-Jouarre in the East) and this line is going to carry the name of its inspirer General CHAUVINEAU.
Although having nothing to do in power with its big sister the Maginot line, and partially unfinished (about 300 blocks were built of whom 200 were able to be
in fighting condition), it will have to undergo the German attack in mid-June 40 and very severe fights will take place there (especially on the N-W axis of
breakthrough), delaying the troops of Reich’s movement in 1 against 100 during 3 days.