Fist City was discovered and settled by Humans. It is unclear why it was named Fist City. It definitely isn't a city, and has little to nothing to do with fists. Sometimes people would use the term "visiting Fist City", when in fact they had no intention of going anywhere near this planet. It was simply a phrase to indicate to someone else that they were about to be beat up. Grif Mansley, a professional Putz, "visited Fist City" several times a day. Rebel Commando Nik Sant loved to give people tickets to Fist City, but also would take them to Bootland and Kneetown as well. All inclusive. This expression resulted in few people visiting Fist City voluntarily, which killed the planet's tourism industry.
Sith Lords Darth Croatia, Darth Goody, Darth Dirtrock, Darth Moonhead, Darth Dee Raper, Darth Douche, were from there- pretty much the entire Sith Gang. There was known no explaination for all the Sith discovered there. Chaelton Gonius and Loni Dias were from there too, but were not Sith Lords.