This is my grandfather from Kolin, Bohumil Steiner, as a soldier. It's clearly World War I.
My grandfather on my mother's side was born in 1871 in Kovansko, Nymburk region. But back then it fell under Kolin. He lived in Kolin, where he was in the textile business, I remember the store. He died on 20th October 1932, a year before the death of my mother, his daughter Marie. Probably in Kolin, because somewhere I had some documents about what Grandma had paid the funeral service, and that was all in Kolin. So he's most likely got to be somewhere in the old Jewish cemetery in Kolin.