Thanks to Lis Bergman for this great information:

1842: Francois-Joseph Declereq bought buildings in Baudour and manufactured porcelain Vases. statues, etc.

1845: Declereq associated himself with a lawyer from Mons, Nicolas Francois Joseph De Fuisseaux.

1848: The partners split ane went their seperate ways. De Fuisseaux now directed "La Manufacture de Porcelaine de Baudour".

1857: Nicolas De Fuisseaux passed away leaving his widow Eleanor Messine to lead the company for the next 25 years making diverse chinaware and insulators. Their son, Fernand De Fuisseaux joined the business and started to add his name to the insulators. Several insulator catalogs are known with only one dated 1890.

1880: The French government requested 270,000 insulators from De Fuisseaux. Over time the contract reached 1 million.

1881: Eleanor passed away leaving the company to her son Fernand. From the periodical "Revue Universelle des Arts - Annuaire de L'Association des Ingenieurs sortis de l'Ecole de Liege - 1883, page 272" we learn that "La Maison De Fuisseaux" exhibited 120 types of insulators at the 1883 "Exposition de Vienne". These insulators were of the finest white porcelain and each insulator ink underglaze marked in red with De Fuisseaux, Baudour and the name of a counry. De Fuisseaux became the largest manufacturer of porcelain insulators, supplying Europe and the world. They took pride in producing insulators using the finest materials and selling them cheaper than other manufacturers.

1927: De Fuisseaux merged with the Societe Anonyme des Pavillions. This company primarily made dinnerware but did make some insulators. Only one "Pavillon" insulator is knowm and it is a spool style.

1934: The Societe Belge de Ceramique "CERABEL" took over the management of the factory at Baudour. They made a diverse variety of products including industrial porcelain. a 1937 catalog shows some Delta style power insulators as well as a suspension. By 1977 the company was nearly bankrupt ane was taken over by NGK Japan.

Four different markings have been observed on insulators. The red script version is likely the earliest, followed by the oval marking (right most). The falcon mark is by far the most commonly seen with the falcon in a circle being quite scarce. De Fuisseaux made insulators for export including styles for France, Australia, Russia, Great Britain, Italy, etc. Given the likely volume produced it is surprising how scarce any De Fuisseaux marked insulator is.