Private Militia
Private militias are organized, commercial fighting forces who arise in a wide variety of different contexts. Sometimes a company with signficant security needs ends up offering protection to other companies as a service before discovering it is more profitable than their core business. Sometimes a nation or state charters a private force - often to unofficially particpate in a nearby conflict. Conversely, sometimes a nation, state or city is unable to finance its current armed force and a dissolved division may offer it self for hire to a nearby company or rival power.
Most private militias find their primary business lies in providing contract support to civil militias, supplementing town guards, providing on-demand security services during special events, or offering flexible, additional protective services in support of trade or infrastructure development. Because of their 'deniable' nature, they are also sometimes used for more aggressive agendas, such as conducting raids to subjugate populations in expansion territories, or supporting conflicts that would otherwise be politically untenable.
A few private militias have an adventurist agenda; assembling former soldiers, explorers and even seasoned adventurers, and sponsoring their expeditions to hunt down fierce mythical beasts, or devle into ancient tombs in search of lost treasures.