Where does “Pra-ha” come from?

Pra-ha (Vietnamese) comes from Czech Praha, from Czech práh, from Old Czech práh, from Proto-Slavic porgъ, from Proto-Balto-Slavic parˀgas, from Proto-Indo-European porg-o-.

Ancestry of “Pra-ha”, step by step

StepLanguageWordMeaning
1CzechPraha—
2Czechpráhdoorstep
3Old Czechpráhthreshold
4Proto-Slavicporgъthreshold, doorstep
5Proto-Balto-Slavicparˀgas—
6Proto-Indo-Europeanporg-o-—
Every word from Proto-Indo-European porg-o- →Every word from Proto-Balto-Slavic parˀgas →Every word from Proto-Slavic porgъ →