This link has been posted on Twitter. IT appears to be a catalogue sale of royal photographs from late 19th century through to modern times. There are some amazing photos with explanations of who is there.
Includes other European royalty
WARNING - it takes time to load as there are over 60 pages with photos. Worth the effort though. Some of the modern pictures are special, including one of QEQM, Princess Margaret, Anne, Andrew and Beatrice together.
Mods - if this should be on another thread, then apologies and please move