The Marches magical traditions
Most Marcher folk have a deep suspicion of magic, believing it to be a path to sorcery and evil. Only blacksmiths and the Landskeepers, steeped in Marcher tradition, are truly exempt from this suspicion.
A Landskeeper is anyone who uses magic to support the territories or the nation as a whole. Some Landskeepers technically lack any real magical ability at all, using traditional rituals and offering good advice and aid to the Marcher folk. A woman that advises on the effective order to rotate your crops, what herbs to use to bring a pregnant pig to term, or where to place a bushel of wheat to keep out evil spirits, is a Landskeeper, whether or not she also employs magic.
The vast majority of Landskeepers form groups of their own, called circles, and keep a certain amount of distance from other Marcher folk. When Landskeepers do associate with Households or market towns directly it is always in pursuit of their own agenda. While they appear to disdain politics, most Landskeepers support the status quo. They view the land as their charge, and their ultimate responsibility is to a territory rather than to any individuals.
Traditionally the Landskeepers support the Marcher armies in wartime. They provide magical enchantments to protect and empower the soldiers of the Marches, as well as healing the injured. Landskeepers act as they will in the service of the greater good, but they possess a license to take unpopular action. Part of their strength, and their ability to operate as they see fit, comes from their control of the magical Dolmans that stand throughout the Marches.
In addition to strengthening the Landskeepers, these great stones anchor powerful enchantments that grant the Marcher soil its extraordinary fertility. Without their influence the Marcher farms would be no more productive than those of any other land. Households who oppose the Landskeepers risk losing their magical support and even their very prosperity. In turn Landskeepers who disrespect the Householders are striking against the fabric of Marcher society that they are generally assumed to be protecting
The Landskeepers do not look well on the new fashion for market towns, a departure from the old ways that the majority have opposed at every turn. The Aldermen of the market towns have little appreciation for the work of the Landskeepers, and their politically protected status makes them hard to influence. Some Landskeeper circles have reached an accommodation with the market towns, but these are usually cautious and shaky associations.
Finally, Landskeepers deal with the Eternals. Most have a deep suspicion of these creatures, which have complex and inscrutable agendas of their own. Most prefer to deal with the Heralds, the human-like servants of the Eternals with whom it is easier to reach a compromise or mutually beneficial accommodation. Places where Heralds appear are often marked with standing stones.
Sorcery
Magic that is designed to harm or curse is referred to as sorcery. Someone who is suspected of using magic or old lore to damage others is a sorcerer and faces shunning or worse. There is a common belief in the Marches that all magic should be done publicly. Only sorcery is done in private - "dark minds find dark places to do dark deeds" so the saying goes. That is not to say that every magical ritual requires an audience, but the more effort the practitioners make to keep people from seeing what they are doing, the more suspect their magic must be.
Some Landskeepers dedicate themselves to tracking down, exposing and destroying sorcerers wherever they may operate. They are called Threshers, and they watch for things that are "wrong." Every farmer knows about separating wheat from chaff, and the Threshers look to separate human wheat from human chaff. They seek out those who are using magic or old lore against the interest of the land. Where crimes are being committed they work with the Beaters to capture the sorcerer and hand them over to Imperial justice. If the sorcerer has not broken any Imperial laws then Rough Music is their punishment, or Shunning if they persist. It falls to the Thresher to convince the folk of the Marches that these punishments are merited, and in many cases to oversee their performance.