Book  (Jun 1992)  Page(s) 173.  
 
Léopold I, Roi des Belges ('Léopold Premier') Hybrid Perpetual. Van Asche 1863. Seedling of 'Général Jacqueminot'. The author cites information from different sources... Velvety purple... Often called a Hybrid China...

Book  (1936)  Page(s) 64.  
 
Belges, Léopold I Roi des (hybrid bourbon) van Assche 1864 Jacqueminot X ? ; glossy purple, very large, double, fine form, fragrance 5/10, olive-green foliage, growth 7/10.

Book  (1936)  Page(s) 413.  
 
Léopold I (hybrid china) ? ? ; velvety purple with scarlet, medium size, double.

Magazine  (1 Jul 1911)  Page(s) 314.  
 
The Parentage of Roses.
The following list of the world's Roses and their parentage has been compiled by Mr. Robert Daniel, 38 Russell Road. Fishponds, Bristol, and by his kind permission we are enabled to publish it...
Leopold I... Hybrid Perpetual, Van Asche, 1863, Seedling General Jacqueminot

Book  (1906)  Page(s) 90.  
 
5.802. Léopold I, Hybride d'Ile Bourbon, Van Asche 1863 pourpre velouté

Book  (1903)  Page(s) 32.  
 
Général Jacqueminot a produit: Alfred Colomb, Alfred de Rougemont, André Leroy, Baron de Rothschild, Camille Bernardin, Charles Lefebvre, Duc d'Edimbourg, Dupuy Jamain, Gloire de Santhenay, Horace Vernet, Le Rhône, Léopold Ier, Maurice Bernardin, Oriflamme de Saint-Louis, Prince Arthur, Richard Smith, Sénateur Vaisse, Triomphe des beaux-arts, Xavier Olibo

Book  (1885)  Page(s) 35.  
 
TRIBE ROSEÆ.
ROSA, Linn.; Rose.
Garden Varieties—
Leopold Premier; hybrid perpetual. Plant in Brisbane Botanic Garden.

Website/Catalog  (1885)  Page(s) 70.  
 
Hybrid Perpetual Roses. 
Leopold Premier Bright dark red, very large and full, fine form

Book  (1882)  Page(s) 17.  
 
Léopold I... Variété à cultiver pour les Expositions de fleurs. Hybride Perpétuel. Van Assche. 1863 Rouge foncé. Fleur grande. Plante vigoureuse.

Website/Catalog  (1880)  Page(s) 238.  
 
Rosiers Hybrides (remontants). Rosa Hybrida.
329. Léopold Ier. — Grande, pleine, très-beau rouge carminé.