In the 19th century, up to 40% of all male workers left the Principality of Lippe every spring. Until autumn, they worked in the north of Germany, the Netherlands, Scandinavia and Eastern Europe on brickworks. The seasonal work of the Lippe brickmakers dates back to the 17th century. The administration of the Principality of Lippe registered them in every detail. For the years from 1778 to 1869, more than 100,000 datapoints on more than 30,000 Zieglers are available in Detmold in the Landesarchiv Nordrhein-Westfalen (LAV NRW), Department of East Westphalia-Lippe. Rarely so much and dense information on seasonal workers with origin and destination is found for such a long and early period to this extent. They are invaluable for the history of migrations, work and the family, but also for genealogists with ancestors from Lippe. You can read more info on iisg.amsterdam or the Ziegler website.