Ludwig Minkus 1826-1917

[giles.enders]

I have recently finished a book 'The Ballets of Ludwig Minkus' 1826-1917 by Robert Letellier.  Minkus is generally regarded as the predecessor to Tchaikovsky, in Russia, for ballet music.  The book is very well researched but and a big but, the author has been able to find out very little about his life, just thirty pages and much of that is dates linked with composition.  My point is really, that he only died in 1917 and his biographical life is almost lost.  We have a similar situation with a number of British composers who have died as recently an the 1950's.  Is there no one place where general biographical material can be placed?