Lantpert (or Landbert or Landfried) (born before 636, died after 680) was the son of Theodo, duke of Bavaria, and Gleisnot of Friuli.
According to the Vita Hamhrammi by Arbeo, bishop of Freising, Lantpert is the murderer of the Saint Emmeram [1].
Fearing her father's wrath, she confided to Emmeram and the saint promised bear the blame, as he was about to travel to Rome.
Lantpert went after Emmeram and greeted him as "bishop and brother-in-law" (Aie, episcope et gener noster!)
Lantpert's deed might be the cause for the Lex Baiuvariorum's unique penalty for killing a bishop: a leaden copy of the corpse was weighed with gold.