Pope Innocent IV had in the 1240s…
1260 CE
Pope Innocent IV had in the 1240s offered King Haakon IV of Norway the opportunity to conquer the peninsula of Sambia, upon which a settlement of Baltic tribes is said to have existed as early as the seventh century.
However, following the personal acceptance of Christianity by Grand Duke Mindaugas of Lithuania, the Teutonic Knights and a group of crusaders from Lübeck have moved into Sambia, founding unopposed a fort in 1252 recorded as Memele castrum (or Memelburg, "Memel Castle"), situated at the mouth of the Curonian Lagoon where it flows into the Baltic Sea.
The fort's construction had been completed in 1253 and Memel garrisoned with troops of the Livonian Order, administered by Deutschmeister Eberhard von Seyne.
Documents for its foundation were signed by Eberhard and Bishop Heinrich von Lützelburg of Courland on July 29, 1252 and August 1, 1252.
Master Conrad von Thierberg uses the fortress as a base for further campaigns along the Neman River and against Samogitia.
Memel had been unsuccessfully besieged by Sambians in 1255, and the scattered Sambians had submitted by 1259.
Memel is colonized by settlers from Holstein, Lübeck, and Dortmund, hence Memel also is known at this time as Neu-Dortmund, or "New Dortmund".
It will soon develop into the main town of the Diocese of Curonia, with a cathedral and at least two parochial churches, but the development of the castle is the dominant priority.
According to different sources, Memel had received Lübeck city rights in 1254 or 1258.
(Since 1945 the Lithuanian name of Klaipėda has been used, and since Lithuania declared independence in 1990 only Klaipėda is used.
The city is Lithuania's only seaport.)