An automated library is disclosed for storing and retrieving data storage cartridges having a plurality of rotatable stacks, all rotatable about parallel axes, each stack being multi-faced and preferably rectangular. A column of cells for storing data cartridges is provided in each of at least two of the faces of the rectangular stacks, and the columns of cells are aligned parallel to the axis of the associated stack. At least one read/write drive is provided for reading and/or writing the data storage cartridges, and preferably a read/write drive is provided at the base of each rotatable stack. A picker is rotatable about an axis parallel to the axes of the rotatable stacks, for accessing the data storage cartridges stored in the cells, and for transporting the cartridges between the cells and a read/write drive. Servo systems rotate the rotatable stacks and the rotatable picker into mutually facing positions for accessing the cells of columns of the stacks with the rotatable picker.