The region of Pomerelia at the eastern end of Pomerania, including Gdańsk (Danzig), was ruled in the 12th and 13th centuries by the Samborides , who were (at least initially) more closely tied to the Kingdom of Poland than were the Griffins. After the death of the last Samboride in 1294, the region was ruled by kings of Poland for a short period, although also claimed by Brandenburg . After the Teutonic takeover in 1308 the region became part of the monastic state of the Teutonic Knights . In the Second Peace of Thorn (1466) most of the region became part of Royal Prussia within the Kingdom of Poland, as it remained until being acquired by the Kingdom of Prussia in the partitions of 1772 and 1793. A small area in the west of Pomerelia, the Lauenburg and Bütow Land (the region of Lębork and Bytów ) was granted to the rulers of Pomerania, although it remained a Polish fief until the First Partition . (A large part of Pomerelia formed the Polish Corridor between the World Wars, and so was not part of the post-war Recovered Territories.)
East Germany decided to upgrade the fortifications in the late 1960s to establish a "modern frontier" that would be far more difficult to cross. Barbed-wire fences were replaced with harder-to-climb expanded metal barriers; directional anti-personnel mines and anti-vehicle ditches blocked the movement of people and vehicles; tripwires and electric signals helped guards to detect escapees; all-weather patrol roads enabled rapid access to any point along the border; and wooden guard towers were replaced with prefabricated concrete towers and observation bunkers.