[2] In ancient Rome, the term referred to provinces at the borders of the Roman Empire (Latin: limitrophus), which were obliged to provide billeting of the limitanei legions deployed on their territory, mostly in limes.
[3] In modern history, it was used to refer to provinces that seceded from the Russian Empire at the end of World War I, during the Russian Civil War (1917–1922), thus forming a kind of belt or cordon sanitaire separating Soviet Russia from the rest of Europe during the interwar period.
[4] Before the Treaty of Versailles was signed on 28 June 1919 and even afterward, it was still unclear which territories of the Russian Empire that were occupied by German troops or engaged in the Russian Civil War would maintain their independence, which they had started to proclaim in late 1917.
The nations were then "the cards to change hands in big political games" and included the Baltic peoples, Poles, Lithuanians, Ukrainians, and Belarusians.
It includes in its list Estonia, Latvia and Lithuania, adding "and, partially, Poland and Finland".