Shanxi: the only human colony ever occupied by an alien race

Shanxi was a Systems Alliance colony sitting beside the Shanxi-Theta mass relay, which made it the departure point for local traffic and, in 2157, the place where humanity met the Turian Hierarchy for the first time. Several battles of the First Contact War were fought there. Until 2186 it held a distinction nobody wanted: the only human colony an alien species had ever occupied. (Mass Effect; Mass Effect 3)

What happened at Shanxi?#

The turians took the colony and held it, and the Alliance took it back, in the only ground occupation of a human world by another species before the Reaper invasion. (Mass Effect; Mass Effect 3)

It started with an expedition that went through the Shanxi-Theta relay and ran into a turian patrol fleet, which destroyed it. One ship survived and reached Shanxi. The commander there sent out a retaliatory force, and that force destroyed the turians it met. What might have stayed a border incident escalated within days. More turian ships came through the relay and took the colony, and the defenders got a message drone away to Arcturus Station before they lost it. (Mass Effect)

The siege#

With turian ships in orbit, the Alliance troops on the ground fought as guerrillas, and the turians ground them down. Every time a marine fire team went out looking for food or supplies, the ships overhead dropped orbital debris and levelled entire city blocks to kill it. The exchange rate did not favour the defenders. (Mass Effect)

The garrison surrendered when the troops were starving and civilians were dying every day, and the turians moved in as occupiers. They then discovered a problem they had brought with them. Turian biology requires them to import all of their food, and the supply line back through the relay was long. (Mass Effect)

They were also working from a bad estimate. Having beaten the handful of ships they had seen, the turians assumed those ships were most of what humanity had. They were not ready for the Second Fleet under Admiral Kastanie Drescher, and the counteroffensive pushed them off the planet. (Mass Effect)

Why there was no war#

The turian response was to begin mobilising for a full-scale war. The Citadel Council intervened before it started. (Mass Effect)

What changed the Council's mind was watching the eviction. The Alliance forces at Shanxi turned out to be well trained, well equipped and adaptable, and a war between them and the turians looked capable of doing serious damage across the galaxy. The Council brokered a truce instead. (Mass Effect)

The reputational effect on humanity ran the other way from the military one. Apart from the krogan, the turians had never met their equals in a war, and Shanxi made the galaxy curious about the species that had just managed it. It also left a deep mutual distrust between humans and turians that lingered long afterwards. (Mass Effect)

The artifact in the caves#

During the siege, a turian research vessel carrying a valuable artifact crash-landed on the planet, and the Hierarchy sent General Desolas to find the ship, the artifact and the researchers. (Mass Effect: Evolution)

The search went badly. Desolas was captured by the human mercenaries Jack Harper, Ben Hislop and Eva Coré, who then hunted down and captured his squad, and in doing so found the cave where the turian researchers had hidden the artifact. The artifact then incapacitated Jack and Ben. That distracted Eva long enough for the turians to free themselves, and Desolas took all three prisoner and reported the find. The turians left Shanxi with the artifact and their captives, who were released later at a post-war prisoner exchange on Arcturus Station. (Mass Effect: Evolution)

General Williams#

The officer who surrendered the colony was General Williams, and the surrender ended his career even though nobody charged him with anything. He left the military eventually and ended up working construction in the colonies. (Mass Effect)

His granddaughter is Ashley Williams, who tells Shepard about him over a drink on Armistice Day. Alliance historians have made attempts to exonerate him in some official way. None of them has come to anything. (Mass Effect)

Afterwards#

The colony kept being useful to people making arguments. Xenophobic groups such as Terra Firma cite it against humanity's growing contact with other species, and when it is put to Terra Firma's leader Charles Saracino that the turian actions at the relay were a misunderstanding, no worse than taking a gun off a child, his answer is that he would take the gun away too, but he would not shoot the child dead. Terra Firma held a rally on Shanxi itself in 2173, and the leadership candidate expected to attend, Claude Menneau, vanished on the way. (Mass Effect)

By 2185 the colony had a regular shuttle route to Nos Astra on Illium, which was delayed indefinitely under security advisories after the attacks on human colonies. During the Reaper War, the relay traffic report on the Broker Terminal lists the data from the Shanxi-Theta relay as unavailable. (Mass Effect 2; Mass Effect 3)