To my knowledge, it all began with a 'Eavy Metal article published in WD136 explaining the painting of bretonnian knights (if you look closely at the second picture, you'll notice the unique apparition of some crossbowmen, knights and men-at-arms probably coming from an older army).
One month later in WD137, several regiments were joining the bretonnian army: les Archers de Brest, les Arbalétriers de Lyons, le Baron d'Angon, l'Ordonnance du Roi, the Feudal levy and les Hommes de Renault. Interesting color schemes, but look at the peasants and the cannon servants: they've received the basic flat colors on each area... and that's all! Rather disappointing considering the usual 'Eavy Metal standards...
Best article of the series IMO, WD138 showed a new unit of knights and three character models: the General, the Army Standard Bearer and a Wizard. Painted with more care than the rank and files, they really stand out and give us a glimpse of what a bretonnian army can be when painted at the highest standards.
As far as I know, WD143 featured the last addition to this army: a regiment of Mounted Spearmen, painted by Neil McIntosh and Matthew Fletcher.
"The horses were all painted different colours, but the techniques for the shading and highlighting were the same. After the base coat was dry, the highlights were gently drybrushed on in lighter shades of the base colour. To smooth out any roughness in the highlights, a thin wash of ink was applied before the reins were painted in Chaos Black. When the black was dry, the reins were painted Skull White, leaving a thin line of black on the edges of the reins to make them stand out against the horse. Finally, the white coat was painted over with Blood Red."
And that's it! I don't think I've ever seen this army again.