Since the second half of the last century art historians, realizing that the image of Rembrandt's work had become blurred with time, have attempted to redefine the artist's significance both as a source of inspiration to other artists and as a great artist in his own right. In order to carry on the work started by previous generations, a group of leading Dutch art historians from the university and museum world joined forces in the late 1960s in order to study afresh the paintings usually ascribed to the artist. The researchers came together in the Rembrandt Research Project which was established to provide the art world with a new standard reference work which would serve the community of art historians for the nearby and long future. They examined the originals of all works attributed to Rembrandt taking full advantage of today's sophisticated techniques including radiography, neutron activation autoradiography, dendrochronology and paint sample analysis -- thereby gaining valuable insight into the genesis and condition of the paintings. The result of this meticulous research is laid down chronologically in the following Volumes: THIS VOLUME: A Corpus of Rembrandt Paintings, Volume I, which deals with works from Rembrandt's early years in Leiden(1629-1631), published in 1982. A Corpus of Rembrandt Paintings, Volume II, covering his first years in Amsterdam (1631-1634), published in 1986. A Corpus of Rembrandt Paintings, Volume III, goes into his later years of reputation (1635-1642), published in 1990. Each Volume consists of a number of Introductory Chapters as well as the full Catalogue of all paintings from the given time period attributed to Rembrandt. In this catalogue eachpainting is discussed and examined in a detailed way, comprising a descriptive, an interpretative and a documentary section. For the authenticity evaluation of the paintings three different categories are used to divide the works in: A. Paintings by Rembrandt, B. Paintings of which Rembrandt's authorship cannot be positively either accepted or rejected, and C. Paintings of which Rembrandt's authorship cannot be accepted. This volume (Volume I) contains 730 pages, starting of with four introductory chapters and discussing 93 paintings. In clear and accessible explanatory text all different paintings are discussed, larded with immaculate images of each painting. Details are shown where possible, as well as the results of modern day technical imaging. In this volume the first ever works by Rembrandt are discussed, also using his etchings as comparison.