The history of the Orcs, Kobolds, Goblins and Hobgoblins is very similar to the early history of the Irish. They have some farming, lots of shore line & stream fishing, and herding of sheep, cows and pigs. The Orcs are divided into a large number of clans, with each clan trying to gain or maintain territory. There are over 150 clans, with each clan being part of a larger tribe. There are a dozen or so tribes, with each having it's own king. Orcs are at war with humans, elves and dwarves of course, but they are also at war with other Orc clans and tribes, Kobolds and such. Orcs are know to temporarily ally themselves with humans, or other humanoids to gain an advantage over other Orc clans or tribes. This has led to lots of in-fighting and distrust.
Humans have often established garrisons to "help" their Orc allies against other Orcs or humanoids. The Orc islands tend to become fighting areas for wars between the human super powers, ala Ireland with regards to William vs James the 2nd.
One of the key events in Orc and humanoid monster history is the plague. In the year ?????, a plague struck humans and dwarves. Orcs were carriers, but were not affected by the plague. The death of many humans led to a slave uprising among the monster humanoids. It was at that point that the bringing of breedable slaves was banned. In the long term, slaves were mostly banned from the human heart lands.
Orcs live in small villages, often built near or as part of a cave complex. The villages are surrounded by wooden palisades. Inside the village, any houses are usually of the Irish round house design which consists of wattle walls and a thatched conical roof.
The worst nightmare for humans and their permanent allies the elves and dwarves would be for the all the Orcs to make a common cause against them.
Last of the Mohecians - capture enemy, keep women as wives / slaves, eat others.