Author's Note

Those who follow my blog as well as the main Friendship is Sufficiently Advanced story will recognize this as a vignette/worldbuilding piece I posted there in the past. Well, there's no particular reason why someone should have to follow my blog to pick up on Advancedverse bits and pieces, so I'm going to include them in here along with the FiSA: Side Stories shorts.

2 The Battle of Eclipse

Battle of Eclipse (-632 P.D.E.): The first and only attempt by the Crystal Empire (expanding south) to seize territory from the Republic of Equestria (expanding north) began and ended with the Battle of Eclipse, in which the hitherto-undefeatable crystal unicorn ability to lase (which, when grouped into phalanxes, permitted them to reduce fortifications and eliminate close formations in a matter of seconds) was countered by the emergency measure - proposed and implemented by the collegium caelis1 - of moving the moon and the sun in syzygy, producing an eclipse lasting three days to take away the ambient light upon which this ability depended.

The peace talks that followed were short, and defined the solution to the problem of the irresistible force meeting the immovable object. To wit, don't.

1. The Republic's magistrates in charge of moving the heavens. Originally composed of a changing number of unicorns, by the time of the Battle of Eclipse, Celestia and Luna were, effectively, the entire permanent membership of the collegium.