Black's Law Dictionary (2nd edition)dictionaries

Landgrave

A name formerly given to those who executed justice on behalf of the German emperors, with regard to the internal policy of the country. It was ap* plied, by way of eminence, to those sovereign princes of the empire who possessed by inheritance certain estates called “land-gravates,” ot which they received investiture from the emperor. Enc. Lond

Source: Black's Law Dictionary 2nd Ed (1910)