Does Primark count as a "department store"? TK Maxx? Or, since the closure of Debenhams and BHS, are we down to John Lewis (true archetype of the department store that sells everything), M&S, and the occasional Harvey Nicks?
Harrods is kind of an exception as it's a single store that's always positioned itself at the very highest end of retail. It will probably outlast most other retailers so long as it retains that cachet.