sentences:  At the same time, land tax exemption ("frälse") was given to those who equipped horsemen for cavalry service, according to the Decree of Alsnö.Coastal defence was provided by several "skeppslag" (literally "ship teams"), a number of farms located in a coastal district that had to furnish both ships and shipmen for service.After the birth of the Swedish Navy in 1522, the system for recruiting shipmen was changed to rely on forced conscription.