'Imperial Leather' was the name of a fragrance first formulated (in the 19th Century?) for one of the Russian Czars. Apparently he was an enthusiastc horseman and wanted a fragrance which would remind him of saddle soap.
At some point (early 20th century?) this fragrance was incorporated into Cusson's soap - hence the 'Imperial Leather' brand of soap.
Cusson's was a family firm with a factory in Salford, UK. In the early 1970s they were bought out by a company of West African merchants called Paterson-Zochonis (PZ); the company is now called 'PZ Cussons'.
Until recently 'Imperial Leather' soap was manufactured in a factory in Nottingham, UK, but a couple of years ago this factory was closed down and manufacture moved to a factory in Thailand. The soap is now based on palm oil rather than tallow.

You may like to reflect on the effects of globalisation on local industries and palm oil plantations on the environment ...