The tree-filled square off the avenue Gabriel was named for Abel-François Poisson, marquis de Marigny, the able brother of Madame de Pompadour who was Director of Buildings for Louis XV. The space was donated to the city of Paris with this specific purpose by a rich stamp-collector, after open-air philatelic exchanges had been evicted from the Palais-Royal in 1864, occasioned by its éléments indésirables1 in the eyes of a Second Empire uneasy about any unsupervised public gatherings. The informal marché was subsequently chased from the Luxembourg Gardens