Indeed.
And yet today the Czech Republic and Slovakia are separate nations as agreed in 1993. Since then they have amicable relations, different languages being among the distinctions. Both were a part of what was once the Austro-Hugarian empire, so borders have changed and changed again, as has governance. And both, though having gone through their "Velvet divorce," cooperate as members of the European Visegrád Group.
I worked a while in Prag, and recommend seeing the city center.
And parts of what is now Ukraine once belonged to Czechoslovakia.
Been to Prague, and to Bratislava, enjoyed both cities.