Where does “ロシア帝国” come from?

ロシア帝国 (Japanese) comes from Japanese ロシア, from Russian Росси́я, from Greek Ῥωσία, from Old East Slavic Русь, from Finnish ruotsi, from Proto-Finnic *roocci, from Old Swedish roþs-, from Old Norse róðr — to row; to separate; loose, sparse, rare.

ロシア帝国 (Japanese): the Russian Empire

Definitions

the Russian Empire

Ancestry of “ロシア帝国”, step by step

ロシア帝国 traces back through two separate lines of ancestry.

via Japanese ロシア

Step	Language	Word	Meaning
1	Japanese	ロシア	Russia
2	Russian	Росси́я	Russia
3	Greek	Ῥωσία	—
4	Old East Slavic	Русь	Rus; Ruthenia
5	Finnish	ruotsi	Swedish
6	Proto-Finnic	*roocci	Swede originally anyone from Roslagen
7	Old Swedish	roþs-	related to rowing
8	Old Norse	róðr	rowing
9	Proto-Germanic	rōþrą	oar; rudder
10	Proto-Indo-European	h₁reh₁-	to row; to separate; loose, sparse, rare

via Japanese 帝国

Step	Language	Word	Meaning
1	Japanese	帝国	empire

Every word from Proto-Indo-European h₁reh₁- →Every word from Old Swedish roþs- →Every word from Proto-Finnic *roocci →