As a result of conquests in 1306 the Slawno land and surrenderings by Swiecowie in 1307 of Slupsk land, all the Middle Pomerania went over under the Brandenburgian rule. On 9th of September 1310, Brandenburg margraves put out location privilege (based on the Lubeck law). On the strength of this privilege, Slupsk received 200 grain-field and margraves released inhabitants from all tributes for a period 10 years, to enable them build new town buildings. In the context of the privilege, citizens were allowed to footloose and duty-free navigation on Slupia River from city to the Baltic Sea. In 1316 the Brandenburgian margrave Waldemar wanting to gain over in favour of West Pomeranian princes, left Wartislaw the Pomerania-Wolgast Slawno-Slupsk land.

In 1329 Slupsk land was crammed (for sum six thousands fines) to Teutonic Knights for a period of twelve years by dukes of Stettin: Otto I and Barnim III. The Teutonic Knights acknowledged the deposit as permanent territorial purchase, counting on that impoverished princes of West Pomeranian would no longer be in a position to buy it up. The Teutonic Knights arranged garrison-town in Slupsk and acceded to enlargement of the plough-land area, buying up individual villages. When the time limit of deposit finished, Bogislaw V - Vartislaw's (prince of Wolgast) son gained a part of pawn-sum and transferred to Teutonic Knights in May 1341.

The Teutonic Order agreed on short-lived prolongation date of redemption, but on very wrong conditions. Slupsk land still stayed a property of Order and in case of breaching the date of redemption, the whole lacking sum of money on was supposed to be left his property. In that difficult situation, Slupsk townsmen succoured, supplying in 1342 lacking sum to take out of pledge. Dukes of West Pomeranian in recognition of merits local habitancy, confirmed in 1348 at full length all laws and privileges of Slupsk society, which by then were granted. Overlords of Slupsk city submitted solemn promise, that Slupsk land would no longer become a deposit of Order the Teutonic Knights.

One acceded to construction of city walls of stone and bricks and also town gates. It was supposed that city walls in significant part arose before 1376. At first, only two town gates existed, which were found on main thoroughfares prolongation (Grodzka and Mostnika Street). The Mill Gate (saved at present) and the Carpenter's Gate in northern line of walls. The New Gate (Nowobramska Street) was made within a later period. The fourth gate lying axled the New Gate, was called the Smith's Gate. It was a wicket in defense wall i.e. the gap portcullis protected. Later, such wickets arose in a greater number, e.g. the Monastic Gate at Dominican cloister or the Owl's Gate in the north - western corner of city walls.

At the same time, one began building of the town hall at the market place. The city streets were narrow and all town area was very densely built-up. This was a reason of bad sanitary condition of the city. The first message about epidemic in Slupsk, comes from 1439. The city was a victim of firestorms, the first time in 1395 and then in 1477. A supreme authority in town was local council, being a trade organ. Town council consisted of three mayors, seven councillors and two bailiffs. The council administered urban possessions, from which town mainly intended on common public interest.

The urban judicature had a two-step capacity. The lower degree matters were led by prefect and the higher degree, so called ‘hanging matters’ - were guided by all the town council members. For super-heavy crimes (murders, rapes, robberies) one punished with death through hanging, cutting or burn at the stake in case of cultivating of magic. In 1476 Słupsk obtained a right of brought in a verdict of death-sentences. One built then on Ustka Street (contemporary name) the gallows, being a warning sign that the city had law to punish for a super-heavy guilt crime.