one's native land; one's homeland
A somewhat literary or formal term for one's home country, often used with a nostalgic or patriotic tone.
It has been ten years since he left his homeland.
I fondly recall the culture of my native land.
It has been ten years since he left his homeland for work.
When the war ended, many soldiers returned to their homeland.
Even far away, I always think fondly of my homeland.
異国 means a foreign land, the opposite of 故国, one's own native country.
故郷 refers to one's hometown or home region, while 故国 refers to one's entire home country, so the two differ in scope despite both meaning 'home'.
Compound of 故 (former, old) and 国 (country). The exact historical derivation is uncertain, but the combination naturally yields the meaning 'old country' or 'homeland'.