A joint Polish-Lithuanian voivodeship of the Polish-Lithuanian Commonwealth, formed from the ~12,000 sq km southeastern rump of the old Duchy of Livonia that the Commonwealth retained after Sweden conquered the Duchy's larger northern part during the Polish-Swedish War (1621-1625); administered in four tracts and represented by six Sejm deputies, covering roughly modern Latgale, Latvia.
Annexed by the Russian Empire (into the Vitebsk Governorate) in the First Partition of Poland, 5 August 1772.
The atlas holds 2 border frames for Inflanty Voivodeship — the shape you scrub through changes in 1621 · 1749.
The standard English-language scholarly history of the Polish-Lithuanian Commonwealth (Volume 1 covers Origins to 1795), including its Baltic/Livonian provinces such as Inflanty. No dedicated English-language monograph on Inflanty Voivodeship alone was found on Open Library (as already noted in the existing duchy_of_livonia record's own reading entry) -- used as a verified, era-appropriate survey.
Same verified survey already used for the predecessor duchy_of_livonia record; continues to cover this rump successor's Commonwealth-era Baltic context through to the 1772 partition.