From 1512 to 1514 or 1515 he worked on the Isenheim altarpiece, apparently in partnership with another Mathis, variously surnamed Nithart, Neithart, von Würzburg (after his place of birth), or Gothardt.
De la 1512-1514 sau 1515 a lucrat la Altarul de la Isenheim, aparent în colaborare cu un alt Mathis, cu numele de familie variind Nithart, Neithart, von Würzburg (după locul său de naștere) sau Gothardt.