Where does “立陶宛” come from?

立陶宛 (Chinese) comes from German Litauen, from Latin Lituania, from Latin -ia, from Latin -ius, from Proto-Italic -jōs, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “立陶宛”, step by step

Step	Language	Word	Meaning
1	German	Litauen	—
2	Latin	Lituania	—
3	Latin	-ia	Used to form a feminine abstract noun, usually...
4	Latin	-ius	forming adjectives from nouns; nominative neuter...
5	Proto-Italic	-jōs	Forms comparative adjectives
6	Proto-Indo-European	-yós	Creates adjectives from noun or verb stems

Every word from Proto-Indo-European -yós →Every word from Latin -ia →Every word from Latin -ius →