Battle of Algeron

The Battle of Algeron was a surprise attack launched against Earth's Starfleet outpost, Starbase 1, by the Romulan Star Empire in May of 2156. (ST reference: Federation: The First 150 Years)

Overview
Three years before the signing of the Coalition Charter, Starfleet started their ambitious Starbase Project to expand bases and to protect Earth colonies. In 2154, Starfleet had chosen a planetoid around the red dwarf Algeron. At first there were problems in transporting labor and material to Algeron, but Starfleet C in C Admiral Avram Gardner and the other species in the coalition saw it's potential and sent ships to help begin construction on Starbase 1. The base was then opened on February 8, 2156.

The planetoid was then revealed by Starfleet engineers to contain vast deposits of castrodinium. Since the other coalition species renounced there claim to Algeron, the castrodinium deposit belonged to Earth. However, the Romulans heard of this discovery and sent agents posing as Vulcans to gather information on the Starbase. Praetor Gileus then hatched a plan and his military and naval Chief of Staff prepare for it despite the Admiral's objections. Gileus then sent subspace message on March 11, 2156, in his name, claiming the Algeron System and that Earth must abandon it. Despite the message, Starfleet held their position. Adm. Gardner then pushed to station a military presence on Algeron, Earth Prime Minister Samuels refused knowing that it could start a war. Despite that, Gardner sent in the Columbia and Excalibur under the guise of "scheduled maintenance". (ST reference: Federation: The First 150 Years)

The Battle
On May 18, 2156, a fleet of 5 Romulan warbir]s under Admiral Mindar entered the Algeron System. (ST reference: Federation: The First 150 Years)