The Elecrian revolutionaries was a separatist movement on the planet of Elecria, that had been preparing for centuries a plan to overthrow the legitimate government of their planet before they were wiped out by the forces of the Galactic Empire.
Actually, the members of this underground organization were the descendants of the rich and influential families of Elecria, that lived about 4000 years before Battle for Yavin and were the supporters of the Elecrian king, that usurped the power in the country several decades before the beginning of the Jedi Civil War.
The King wanted to be treated as a ruler of a new Elecrian Empire, for this he began the so-called crusade against the planets of the Senb'An'Tiin star system. It began with the destruction of a small colony on the planet of Vur'Lua, that was a simple test to prove that it was proper time to start the invasion.
The Elecrian dictator made a secret treaty with the Sith in order to expand the territories of his Empire, with the help of the Sith soldiers it was far more than easy. In return he granted the construction of Sith military facilities on Elecria.
But the war resulted in complete elimination of the existing governmental organization after the first rebel movements appeared on the planets of Uthel and Shiib: the Sith were removed from the sector, their bases destroyed, the Emperor killed, and the very idea of creating the Elecrian Empire was banned forever.
However several of the main supporters of the old order survived the crisis and formed their own political movement. They changed their names and started a new life, but for many years their true activities remained latent, even though they tried to make some trouble for their enemies under one name or another.
After 25 BBY they met a new ally: somebody sent a messenger - ZID-17 - to make a curious proposal for them. They could not refuse it, because it was the only chance for them to have the power on Elecria back in their hands. In return they had to support the Separatist Movement of Count Dooku.
They declared their official support of the Confederacy of Independent systems in 21 BBY during their operation on Elecria to remove the local authorities, but the Republic Forces arrived in time to exterminate any possible presence of the CIS on the planet.
All known members of this organization were killed together with other separatists in 19 BBY.