Though compositional structure – which here means specifically the placement of divine figures – is an essential aspect of Tibetan painting, this theme has rarely been discussed or described by scholars. The conventions for depicting lineages of teachers in particular must be carefully taken into account when documenting thang kas that contain lineages with inscriptions. The historian should carry out, if possible: (1) decipherment of inscriptions, recording names; (2) historical identification of individual masters, furnishing dates if known; (3A) identification of the lineage, and (3B) listing its members in chronological order (i.e., following the sequence of lineal descent); (4) diagramming the position of all figures, following the numbering of step three. The present article classifies and describes the lineage structures found in the vast majority of paintings with lineages. Understanding lineage structure through these four steps allows the historian to identify the religious teacher and approximate generation of the patron who commissioned the painting, essential steps toward restoring the painting to its lost historical context. (Than Garson 2005-09-22)