Don't Pass Line
The Don't Pass Line was one of the most pivotal battles of the Kamian Succession Wars, and widely credited with halting the Kamian Expansion. The battle occured in A.Y. 6800, twelve years before the official end of hostilities.
The Kamians were infamous for using a "lightning attack" strategy of staging large numbers of forces behind their own defensive line, then launching an all-out attack on an enemy position; moving as fast as possible; and hitting with maximum force. Similar tactics date back to the Mage Wars, though they might have been employed in Antiquity.
The Kamians had become well-known for this tactic, and the typical Foundation response thus far had been a counter-tactic called Scorched Earth, in which Gudersnipe or Alliance forces retreated in the face of the lightning attack and destroyed everything they could not take with them. This starved the Kamians of crucial facilities and resouces, and helped slow the advance.
In this particular battle, the Admiral Comodore of the region, Roberto Gailen decided enough was enough: the line would be drawn beyond which Gudersnipe would not retreat.
The Kamians use a battle group system based upon 4 capital ships and eight support ships. By that division, they assembled 700 battle groups, or 8,400 ships.
Crimson Blade battle groups at the time were 52 ships, and including the 8th Fleet of which he was in command, Gailen managed to gather 200, totalling 10,400 ships. He added to that 80 more Coalition battle groups of 20 ships each for an additional 1,600 ships, as well as forces conscripted from the local Merchant Marine fleet. These would be used primarily for transport and combat observation, and were organized into 10-ship groups around armament to add 185 additional battle groups or 1,850 more ships. In total, Gailen had ammassed 13,850 ships to defend three solar systems.
In addition, the defensive force included 27 heavily-armed instalations and 600 orbital weapons platforms, as well as over 5,000,000 mines.
Gailen swore that the Kamians would not pass his line, and true to his words, the defenses held. In a brutal, 16-day battle, Gailen directed a wide and adaptable battle-strategy aimed at grinding the Kamian forces to dust.
It was the largest space-battle to date, and the first time in history a Kamian lighting attack was successfully stopped.