Galactic Empire is the first game in the Galactic Saga. It is the game that launched Brøderbund software, and though little-known today, it was a forefather of modern space conquest games such as Spaceward Ho! and Master of Orion. Doug Carlston wrote Galactic Empire while working as a lawyer. After finishing the program Empire he left his job to begin work for Brøderbund.
Originally written for the TRS-80, Galactic Empire was also ported to the Apple II and the Atari 400/800. A Macintosh port was developed by Cary Torkelson, with permission from Doug Carlston.
Subsequent games in the Galactic Saga are Galactic Trader, Galactic Revolution, and Tawala's Last Redoubt.
The game navigation uses a list of planets with names beginning with a unique letter of the alphabet for easy access. The 'R' key is reserved for 'Return', and 'Q' for 'Quit.' The player has one fleet which travels from planet to planet, beginning with the home world 'Galactica.' Conquered planets can be taxed and are also a source for recruiting troops to support future conquests. Each planet has a technology level above or below Galactica standard, which makes it easier or harder to conquer. It takes time to travel between planets to collect taxes and troops to conquer new planets. The player has 999 years to take the galaxy.
Source: Wikipedia, "Galactic Empire (Brøderbund video game)", available under the CC-BY-SA License.
Game Manual
As commander of Galactica's Imperial Forces, your mission is to conquer and hold the 20 inhabited worlds of the Central Galactic System. Aboard the fleet flagship you are ably assisted by your senior officers and the ship's onboard computer. Computer Central contains star maps of the galaxy and a planetary directory. It also keeps track of all scout ships on missions and on the status of work orders for new star ships at your shipyards around the galaxy. Lieutenant Starbuck is your officer charged with responsibility for all scouting missions. Lieutenant Bayliss is the staff officer responsible for planetside activities. His duties range from enlisting new troops to collecting taxes to contracting for new ships for the fleet. Your navigator is Sergeant Kirman, and you also have aboard a medical doctor, Doctor Henderson, who is an expert in suspended animation techniques.
This is important, for one immutable scientific fact stands between you and the empire you wish to carve out--no one yet has discovered the secret to faster-than-light travel. Even the tiny Central Galactic System is sixty-odd light years wide. Logistics have always been an important facet of any military campaign, and that has not changed. Careful planning is essential if you are to keep your fleet replenished as it moves throughout the galaxy.
Because cryonics and high speed space travel stretch the average life span, you will have 1000 years to complete your mission. Except during periods of travel or hibernation, you will actually have about 4 minutes for each year of your command.