革命政府は、民衆から兵をつのって防戦するとともに、共和政治を確立して、捕らえていたルイ１６世を処刑しました。

、、、。

The revolutionary government recruited soldiers from the populace to fight defensively, while also establishing a republic and executing Louis XVI, whom they had captured.

Literal

Revolution government [topic-は], populace [from-から] soldiers [object-を] recruiting fight-defensively [together-with-とともに], republic-politics [object-を] establishing, captured-[state-ていた] Louis XVI [object-を] executed.

A history-textbook sentence about the French Revolution. 兵をつのる ('to recruit soldiers') uses 募る in its original military sense. ~するとともに ('while also doing') links simultaneous or coordinated actions — more formal than ~ながら. 捕らえていた uses ~ていた for a state persisting up to the main event. Full-width numerals (１６世) are standard in Japanese text.