The Gamemaster series of games was put out by Milton Bradley in the 1980s. They were known for their big boxes, big boards and tons of plasic pieces. The quality of these "light wargames" had not been seen before, and likely served as the inspiration for many games released later by publishers such as Eagle Games, the later Avalon Hill, and especially Fantasy Flight Games.
Axis & Allies became the popular favorite of the five, and even received multiple unofficial, third-party expansions. Avalon Hill later released several spin-off games, and in 2004, a revised version of the original game was released.
In 2005, Eagle Games released an updated version of Conquest Of the Empire, including two sets of rules: a revised version of the original rules, and an alternate set based on Martin Wallace's Struggle Of Empires.