While scholars agree that Z'graggen's lexicostatistical subgrouping of the South Adelbert languages is inaccurate in many respects, to date there has been no published subgrouping based on application of the comparative method. In this paper, I examine the history of a subset of eight South Adelbert languages, for which I propose the name Sogeram. I reconstruct the phonological system and 102 lexemes of Proto-Sogeram and argue, primarily on the basis of shared phonological innovations, for a tripartite split into West, Central, and East Sogeram branches, and for subsequent splits and developments within each branch. One innovation of potential theoretical interest is the loss of all word-initial consonants, regardless of place or manner of articulation, from polysyllabic words in West Sogeram.