I don't believe I ever met F.W. Lancaster but I so value his work. His books and articles are so practical and useful. Clearly written. They're pretty much timeless, too. For example, his book: Lancaster, F. W. (1993). If you want to evaluate your library (2nd ed.). Champaign, IL: University of Illinois Graduate School of Library and Information Science, is on my bookshelf at work, and I do pull it down from time to time to reference various parts.
There's a blog post from UIUC with his bio.