Grave is the slowest and most solemn of all tempo markings. It calls for an extremely slow pace with a heavy, serious character — the word itself means grave or solemn in Italian. Typical metronome markings for grave fall below 40 BPM.
The marking is relatively rare compared to other slow tempos like adagio or largo. When it does appear, it signals music of the utmost gravity and weight. Beethoven's Pathétique Sonata opens with a grave introduction before launching into the allegro, and the contrast between the two tempos creates powerful dramatic effect.