Walter Percy Sladen was the son of a wealthy merchant from Halifax. The young man's interest in echinoderms - starfish, sea urchins and related creatures - was awakened during trips to the Yorkshire coast. He later toured most of the major European museums that held specimens and spent several months studying the live animals at the Zoological Station in Naples.
His reputation brought him to the attention of Sir Charles Wyville Thomson. He was looking for someone to describe the enormous wealth of echinoderm material collected on the Challenger oceanographic survey. This task he undertook, duly completed and published in 1889. However, the hours of careful work, often very late at night, caused him ill health.
Sladen died in Florence in 1900 whilst still a young man. His widow, Constance, wanted the collection to remain together and accessible for study, so she presented it to the Royal Albert Memorial Museum and Art Gallery in 1903.
The Percy Sladen collection attracts researchers from around the world. It is believed to be the largest and most comprehensive echinoderm collection outside the Natural History Museum, London. In addition it includes an outstanding group of microscope slide preparations from the collection of W.B. Carpenter collected on the HMS Challenger and other voyages.