Germany is marking the Day of German Unity on October 3, with the national holiday generating massive online interest as hundreds of thousands of people search for information about the celebrations.
This year's central ceremony is taking place in Bremen, where Germany's political leadership gathered to commemorate 36 years since reunification.
President Frank Walter Steinmeier used his address to deliver a strong warning about the state of German democracy.
According to Tagesschau, Steinmeier warned that political extremism and increasingly aggressive rhetoric threaten not only freedom and democracy but also Germany's unity. He urged Germans to defend democratic institutions and fundamental rights.
The official celebrations began with an ecumenical service at Bremen's St. Peter's Cathedral. Religious leaders also warned against growing polarization and called for greater social cohesion.
The celebrations extend far beyond the official ceremony. Bremen is hosting a large public festival across the city center and along the Weser, with music, theater, discussions and events on more than 100 stages.
Organizers expect more than 400,000 visitors during the weekend, according to Tagesschau.
The Day of German Unity commemorates the reunification of East and West Germany on October 3, 1990, and remains one of the country's most important national holidays.
Interest has surged dramatically online around this year's anniversary. Google Trends shows more than 500,000 searches for “Tag der Deutschen Einheit,” with related searches focusing on Steinmeier, demonstrations and Bremen.
The celebrations also come amid continuing debate over differences between eastern and western Germany. Government commissioner Elisabeth Kaiser said remaining inequalities in income, wealth and representation in senior positions still need to be addressed.
For millions of Germans, however, October 3 remains above all a celebration of the moment when a divided country formally became one again.
