Talk:noch ist Polen nicht verloren

From when this idiom began to be used--Propatriamori (talk) 00:26, 2 July 2018 (UTC)?

I can't say for sure, but I'd strongly suspect the early to mid 19th century when there was a huge wave of pro-Polish sentiment (called Polenschwärmerei) that started with the November Uprising in 1830. The Polish national anthem was translated into German and was sung at the Hambacher Fest and the National Committee under Lelewel sent a letter of solidarity. This also lasted on for some decades, but, of course, German nationalism became less pro-Polish after the foundation of the Empire in 1871. Nevertheless it's an important part of German-Polish history that is often forgotten in both countries.