Born in Hungary, Rav Schiller-Szinessy became a professor at Cambridge. The only photo of him I could find shows him wearing a graduation cap. I'm guessing it was not his everyday hat.
Even though he was born in Germany, Rav Adler became the Chief Rabbi of the British Empire. Unlike his Western European bretheren, he wore a fancy "wheel cap" style hat, similar to those worn in Southeastern Europe. But I suspect this has more to do with the British prediliction for fancy hats.