Zorashia is a country who no longer exists. They were engaged in a brutal civil war that eventually lead to the downfall of the country. Greta is originally from here. About half a year after, Greta was sent to Svelera; the citizens over threw the government.
Differences in anime
In Episode 93 of the anime, the country seems to still exist and Izura was the queen of the country who died during a war. A man from Zorashia comes to take Greta back because the country is in need of a ruler. The man ends up not taking her back because she is happy in Shin Makoku.