The confusion was created by the many painters named Francken, some poor attributions, and a portrait by Anthony van Dyck of a certain Johannes Baptist Franck, aged 32, of whom nothing more is known.
He is sometimes said to be the same as Hans Francken (born in 1581), another obscure member of the same family.
In art histories from the 18th and 19th century like Michael Bryan's Bryan's dictionary of painters and engravers (1886) he received a lengthy lemma: Other dictionaries and encyclopedias which included him were e.g. Friedrich Müller's Die Künstler aller Zeiten und Völker (1860) and Jean-Baptiste Descamps' La Vie des Peintres Flamands (1754) (as "Jean-Baptiste Franck").
The Old St. John's Hospital in Bruges listed two of his works in their collection in 1861.
[2] Already in the 1857-1864 work by Christiaan Kramm, De levens en werken der Hollandsche en Vlaamsche kunstschilders, beeldhouwers, graveurs en bouwmeesters, van den vroegsten tot op onzen tijd, doubts were formulated about the biographical details given about this painter, which didn't match the dates given for some of his works, or the age given on the Van Dyck painting.