This thesis examines Rogier Van Der Weyden's two unique fifteenth century Crucifixions, The Crucified Christ Between the Virgin and Saint John and The Diptych of the Crucifixion, in light of Carthusian beliefs, practices and relevant devotional texts. The specific text used to support this examination is the Vita Christi by Ludolph of Saxony, which in part deals specifically with the Hours of the Passion. Ludolph's text is given visual form in Rogier's paintings and supports the assertion that Rogier and Ludolph were connected by a shared belief and worldview. Key aspects of Rogier's life, supported by original documentation- familial ties, associates, patrons, use of finances, and his close involvement with the Carthusians-- support this assertion. Other models of connections of belief, evidenced through artist's work, are corroborated in the work of Grunewald, Sluter and Durer.