Abstract: This year is the 50th anniversary of the birth of the laser. The invention and development of the laser, which has many and varied physical and performance characteristics, has had a profound effect on modern electro-optical technology. Looking in detail at the early pioneers who contributed to the advancement of the laser over the past 50 years, we can see how lasers have evolved and their tremendous influence on a wide range of disciplines and applications. We are indebted to the Society of Photo-Optical Instrumentation Engineers (SPIE) for their documentation of the evolution in innumerable conferences, handbooks and scientific papers.