For the last 150 years the Gospel of Marcion has been considered to be an abbreviated edition of the canonical Luke. This article renews the reverse hypothesis of Marcion's priority to Luke, Luke therefore being a revised and enlarged edition of Marcion. The arguments include a critique of the traditional view, based primarily on its failure to verify Marcion's alleged editorial concept on the basis of his text, and to solve the problem what Marcion would have done with Acts. On the other hand, the beginning of Luke (esp. 1.1–4; 4.16–30) suggests that the differences between both editions are best understood as Lukan additions to Marcion rather than Marcionite abbreviations of Luke. This Lukan, anti-Marcionite revision is very close to the Four-Gospel-collection and first created the unity of Luke–Acts.