He was Duke of Gallièri in Genoa, but used the pseudonym "Ferrary"; his calling card reads "Philipp von Ferrary". Collectors and dealers usually say just "Ferrary".
He started collecting in his youth, then inherited a fortune, which he dedicated to the purchase of rare stamps. He lived in Paris, but travelled frequently, meeting with dealers along the way, and often paying them in gold on the spot.
Wishing to make his collection accessible to the public, on January 30, 1915 he willed it to the Postmuseum in Berlin, along with annual funds for maintenance. But as a citizen of Austria living in France, World War I put him at risk, and leaving his several hundred albums in the Austrian embassy, he fled to Switzerland, where he soon after died.
After the war, the French government confiscated Ferrary's collection, claiming it as a war reparation. The massive assemblage was auctioned off between 1921 and 1926, in 14 separate sales, realizing over 25 million francs. Many of the rare stamps of today proudly bear an "ex-Ferrary" in their provenance.