1566     Creation of the Herbarium by Petrus Cadé.

1568     Annotations made by Ischa Cadé.

1609     Some plant species were added and further annotations made. Local names were added. (perhaps by Ischa Cadé?)

1600?   Herbarium was bought by Jan de Vriendt, who paid 8 schellingen.

????      Herbarium was probably part of a privately library collection in Amsterdam. This library collection was sold at an auction and came (later?) in the possession of C.K. Ogden (UK). Exact dates of transfers are not known. On several pages (e.g. 1B, 2A, 3A, 6B, 13A, 13B) old english common names are added. These annotations could be an indication that the herbarium already came in it's early history in possesion of an English speaking person.

1957     The Ogden collection was bought by the Louise M. Darling Biomedical Library at the University in Los Angeles (UCLA) and the herbarium was stored in the UCLA-herbarium.

1973     Herbarium was shown by Dr. Mildred Mathias (Director Botanical Garden, UCLA) to Prof. F. Stafleu, working at that time on Taxonomic Literature. The latter cruised the States after co-organizing the first International Congress of Systematic and Evolutionary Biology in Boulder, Colorado, 4-12 Aug 1973.

1973      At the same time, Prof. Stafleu was shown the Antonius Gaymans Herbarium (± 1630-1680), the third oldest Dutch plant collection, also present at UCLA. This herbarium was brought to the Netherlands by Prof. A. Gibson, successor of Dr. M. Mathias, in 1983 and is now present at the NHN-Leiden branch (L) (Sosef et al. 1987, Sosef & Heniger 1989).

1976     Publication in Taxonomic Literature by Stafleu & Cowan. The Herbarium is attributed to Peter Coudenberg.

1979     Herbarium was donated to Prof. F. Stafleu. Stafleu in his turn donated the Herbarium to Prof. F. Verdoorn, leading the Biohistorical Institute at the Utrecht University.

1979     Letter from Dr. J. Heniger to L.J. Vandewiele concerning the comparison of different handwritings that occur in the Herbarium with those of P. van Coudenberghe and J. Camerarius. In this period Dr. J. Heniger added annotation slips to some of the detached collections.

1998     Rediscovery of the Herbarium during the move of the Biohistorical Institute from a historical university building in the Utrecht city centre to the University campus. The Herbarium was found on the loft, behind a radiator. The Herbarium was donated to Prof. P.J.M. Maas, head of the Plant Systematics Department, and transferred to the library of that institute.

1998     First set of photographs taken by G. Thijsse, head of collections, NHN – Leiden.

2001     Student research by M. Christenhusz. Taxonomy of collections was updated and checked. Herbarium was attributed to Petrus Cadé. Results were reported in Christenhusz (2004).

2003     Funds were found through the Dutch ‘Pieter Langerhuizen Lambertuszoon Fonds', for website building and further research in the history of the Petrus Cadé Herbarium by Dr. R.C. Ek. Recommendations for restoration and storage were made.

2004     Funds were obtained via the 'Alberta Mennega Stichting' for restoration and providing the book with a special box. Restoration was completed in July.