Poczet

Poczet (fellowship or retinue) (plural Poczty) was the smallest organized unit of soldiers in Kingdom of Poland and Polish-Lithuanian Commonwealth from the 15th until the 18th century. The name of a medium or heavy-cavalry soldiers in poczet was pocztowy.

In the cavalry, each poczet was commanded by a towarzysz husarski or towarzysz pancerny. Several Poczets were combined to form larger units such as the Chorągiew (Company, or more correctly, the equivalent of the medieval Lances fournies).

Pocztowy was an assistant and subordinate of the Towarzysz, in some respects similar to more ancient knight's servant - page or squire. He was armoured like his superior, but fought in the second or third line and was responsible for guarding his back and flanks in a battle.

...
Wikipedia