How did stronger German princes cause some cities to leave the Hanseatic League?

The premise that stronger German princes caused cities to leave the Hanseatic League is accurate. As the power of territorial princes grew within Germany during the 15th century, it increasingly conflicted with the autonomy of the member cities.

This strengthening of princely authority forced several cities to detach from the league, most notably Berlin and other towns within the Brandenburg region, which were compelled to withdraw.1

This shift was part of a broader decline in the league's unity. As external pressures from rising national powers and foreign competitors like the Dutch and English mounted, the league struggled to maintain a common purpose. While some cities remained committed to the league's restrictive policies, others—such as those centered on Cologne or Danzig—found their own economic interests increasingly aligned with foreign traders or were otherwise unwilling to support the extreme measures demanded by the league's leadership in Lübeck.1