The modern spelling for the name is "Jelacic"; but the more familiar spelling may come from the fine vintage book about the Balkans, "Black Lamb, Gray Falcon", by Rebecca West, from 1937-41. The officer stands, mounted, in the market square, Jelacic Square.
Yellatchitch-Jelacic according to "Black Lamb" is the 1848 hero who had been appointed Ban of Croatia. He was a Croat General who brilliantly repelled the Hungarians, crushing their rebellion, and thus preserved the Austrian Empire from the Hungarians. They later joined forces as the Austro-Hungarian Empire, but at this time there was conflict.
"Ban" means "Viceroy". The story is important for its human betrayal side: Jelacic was then promptly shoved aside, as other powerful interests and people took over. See knigite.abv.bg/en/rw/rw_epilogue1., the 1937-41 book, "Black Lamb and Grey Falcon," by Rebecca West at the paperback version pages 53-56, Penguin Books 1994.
Read about the old Zagreb there: here is the Epilogue at knigite.abv.bg/en/rw/rw_epilogue1, Old Zagreb, "Black Lamb and Grey Falcon."
Travel reading. I took the paperback, but cut it in half. It was too thick as a single paperback, too heavy as a hardback. Kept both halves,