Human society in Xanth
The known human history of Xanth began at year 0 with the First Wave of humans crossing from Mundania. However, humans had previously visited the land of Xanth several thousand years earlier, before Xanth was separated from Mundania. Unfortunately, human crossbreeding with other species in Xanth brought them to extinction. Upon the reconnection of Xanth with Mundania, limited human migration to Xanth is seen until the First Wave. Most evidence of these migrations have been long lost to most written histories. 
Most human waves were waves of conquest. Of the 15 known waves, only the Fourth Wave and Thirteenth Wave were known as peaceful waves. Many of the waves between the Fourth and Twelveth Waves were repeated attempts at conquest.
The first wave of humans moved in, cutting down trees and killing animals. Many of the now more endangered species in Xanth were hunted nearly to extinction by the First Wave. First Wavers, as they are often called, had no magic of their own. When they began realizing the magical opportunities Xanth provided, they began looking for ways to use it, but also avoid being too close to it. They burned forests, killed magical life, built walls, planted mundane crops and raised mundance livestock. They even brought mundane women from home, or raided nearby mundane villages, to help raise families. The ruins near North Village are only physical evidence left of the First Wavers.
The children of the First Wavers were the first humans in Xanth to have magic. First Wavers were initially resistant, but eventually found benefits to these talents. One child could transform lead into gold, leading to a massive search throughout Xanth and finally into Mundania for lead. In the process, they attracted the attention of more Mundanians, leading to the Second Wave in the year 35.
The second wave of humans quickly moved in and killed all of the First Wavers except for the women, whom they took for themselves. Initially looking for a machine to change lead into gold, they didn't know until it was too late that they had killed the very thing they were looking for. The Second Wavers started off raping and pillaging Xanth, even killing centaurs for meat. Eventually, the centaurs fought back and things settled down for several generations. Magician Merlin may have been born to a Second Waver.
The Third Wavers came with much of the same intentions as the second Wavers, killing all but the women and some children. The difference during this invasion was that the women had magic, and successfully fought off all of the invaders over several years. They were left widows, physically and emotionally scarred. Strong-willed and determined, the Second Wave women began the search for suitable men to bring into Xanth. Magician Roogna may have been born to a Third Waver.
The Fourth Wave was considered a peaceful wave. It was an organized search for strong, intelligent, just and kind men to bring into Xanth to help rebuild the settlement. Not all of the men stayed, but many did, helping to establish a colony of humans dedicated to protecting Xanth. Some Fourth Wavers were also young women brought in to help prevent inbreeding with some of the younger survivors. Common belief among historians is that the first great Magicians came from the Fourth Wave.
Fifth - Eleventh Waves
Many of the waves that followed the Fourth Wave were repeated attempts at conquest by groups of Mundanians who happened to come across Xanth at random.
The Twelveth Wave was another attempt at conquest. It became known as the Last Wave as it was the last wave to be seen until Trent became King. The Shieldstone was established after this wave to protect Xanth from future waves.
This wave consisted of the Mundanian army that Trent had developed during his exile in Mundania. After being crowned King, Trent deactivates the Shieldstone and invites them into Xanth and promised them farmland. Despite being an army, they came willingly and in peace.
Also known as the Next Wave.
Also known as the Black Wave.
Much of the human history of Xanth is split up into three periods:
Not much is known about the society of Xanth before Gromden's reign, but that time period (despite the Waves) is considered the first Golden Age.
This period started with the Yin-Yang's reign and finally ended when Trent inherited the throne. During this period, much is unknown, except that Magician Ebnez ended the waves and tried to bring some cultural changes to the human kingdom. Also Humfrey instituted the Council of Elders during his reign. The only other thing known is that the Storm King would banish any human without a magic talent, as he did with Bink.