Groupchats and Medieval Merchant Leagues

A decentralized group can gather together to reap the benefits of collective bargaining, even if they're all over the world.

We've talked about the Hansa, a medieval merchant league, before.

They started as groups of merchants from various towns who travelled in numbers to protect themselves from robbers and the like.

However, I've not had a single, simple source to point anyone to (besides Wikipedia).

Works in Progress released one recently, and it's a great summary.