Persistent object oriented architectures have been researched for many years, deriving initially from the Manchester University Atlas machine. In reality however, few actual implementations of persistent architectures exist. In the first half of this paper an examination of four well known designs is examined, namely the SYSTEM/38, MONADS, MUTABOR, and the Rekursiv. Each machine├Ľ object management model is explained, along with an analysis of the design decisions made. Following this, a discussion concerning the ideal persistent architecture is presented, suggesting design decisions which should be considered in any future persistent architecture.