This paper presents an Optimality Theoretic (Prince and Smolensky1993; McCarthy and Prince 1995) analysis of diachronic phonological change as the reranking of violable constraints, taking thee mergence of word-medial geminates in West Germanic as a case study. West Germanic is characterized by, among other things, the gemination of all consonants – except *r – after a short vowel and before *j (Gmc. *skapjan > OS skeppian, OE scieppan vs. Got. skapjan, ON skepja ’tocreate‘) and the gemination of voiceless stops before *r and*l (*akr- > OHG akkar, OS akkar vs. Got. akrs, ON akr ’field‘). Evidence from versification and word division in original documents suggests that all Germanic dialects favored bimoraic stressed syllables, syllabifying *skapjan as *skap.jan, for example. This often resulted in faulty syllable contacts in which the coda consonant was less sonorous than the following onset. Murray and Vennemann (1983) propose that geminates arose in order to repair such faulty syllable contacts (e.g., *skap.jan > *skap.pjan),but their analysis fails to satisfactorily account for the full scope of the West Germanic Gemination. I propose here that while gemination before *r and *l was driven by unfavorable sonority differences at syllable margins, the more pervasive appearance of geminates before *j simply resulted from a well-attested Germanic dispreference for *j in onset-initial position.