Barely 50 years after the birth of enterprise computing, cloud computing promises to transform computing into a utility delivered over the internet. A historical perspective is instructive in order to properly evaluate the impact of cloud computing, as well as learn the right lessons from the past. We first trace the history of enterprise computing from the early mainframes, to client-server computing and 3-tier architectures. Next we examine how the internet evolved into a computing platform for enterprise applications, naturally leading to Software as a Service and culminating (so far) in what we are now calling cloud computing. Finally we describe how the ‘enterprise architecture’ function within IT departments has evolved over time, playing a critical role in managing transitions to new technologies, such as cloud computing.