The evolution of the Frequency Standards and Metrology symposium and its physics

In this paper I recall some of the earlier developments in the physics and measurement of atomic frequency standards and clocks, as revealed in presentations at past Frequency Standards and Metrology (FSM) symposia in this series. Coverage is not meant to be comprehensive; unfortunately, I can select only a relatively small number of representative examples of work that I felt stimulated many of the major areas of interest since the first meeting in 1971. (paper)