Catenanes are molecules consisting of two or more rings that are mechanically interlocked requiring the cleavage of a chemical bond to separate the macrocyclic components. Initial attempts to synthesize these aesthetically pleasing molecules via nontemplated methods were blighted by low yields and lengthy syntheses, and it took Sauvage's use of the copper(I) cation as a template for the synthesis of a [2]catenane to ignite intense research activity in this field. This chapter summarizes this groundbreaking work and the array of template interactions such as metal cation, charge transfer π-π stacking, hydrogen bonding, and anion coordination that have since been utilized to produce catenanes. Attention is then turned toward the progress that has been made in the practical applications of these mechanically chain linked structures, such as the control of their molecular motion, immobilization onto surfaces, and efforts to incorporate them into extended structures such as polymers and metal organic frameworks.