One of the oldest words in the German language, 'Herz' descends in an unbroken line from Proto-Indo-European *ḱḗr, its initial sound transformed by Grimm's Law from the same root that gave Latin 'cor' and Greek 'kardía.'
The heart — both the muscular organ that pumps blood and the metaphorical seat of emotion, courage, and the innermost self. One of the oldest and most fundamental words in the German language.
German 'Herz' is one of the core inherited vocabulary items of the Germanic language family, traceable in an unbroken line from Proto-Indo-European *ḱḗr (heart) through Proto-Germanic *hertō to Old High German 'herza.' The word has cognates across virtually every branch of the Indo-European family, from Latin 'cor' to Greek 'kardía' to Sanskrit 'hṛd.' The shift from PIE *ḱ to Germanic *h reflects Grimm's Law, the systematic sound change that
The German word 'Barmherzigkeit' (mercy, compassion) literally means 'warm-heartedness' — from 'barm' (bosom/warm) + 'herzig' (hearted). Martin Luther chose this word deliberately in his Bible translation, and it became so central to German Protestant theology that it shaped how an entire culture understood the concept of divine compassion.