This was actually the anthem of the Austrian monarchy (introduced in 1797, in official use from 1826 until the end of the monarchy in 1918). Some Austrians are still hearing the original text ("Gott erhalte, Gott beschütze / Unsern Kaiser, unser Land!") whenever the "Deutschlandlied" is played.

Before the "Deutschlandlied" was introduced in 1922, the Prussian anthem "Heil Dir im Siegerkranz" was in common, but not official use in the German empire (1871). This one used, like many others, the melody of Britain's God Save the King/Queen.

[Edit] The anthem of the Habsburg-empire is a bit tricky in terms of plagiarism: The melody was composed by Joseph Haydn in commission by Franz II. (later Franz I.), but was also part of the "Kaiserquartett" (op. 76 no. 3, also 1797). Here, there are some similarities to an earlier composition by Mozart ("Exsultate, jubilate").