Given the large number of posts in the series and the fact that it runs in roughly chronological order I've included below a recap of all the parts of this Brief History of Tactics for convenience.
Positional Terminology - Part 1
Positional Terminology - Part 2
Positional Terminology - Part 3
The Danubian School
The Magical Magyars
Brazil and the Flat Back Four
The Wingless Wonders
Brazil and the five "10s"
The Death of the Sweeper
Recent Developments and Beyond