German-Turkish ties have plunged to an all-time low since last year's failed coup against President Recep Tayyip Erdogan and the subsequent crackdown on alleged plotters and state enemies.
The escalating tensions have divided the three million ethnic Turks living in Europe's top economy, the largest diaspora abroad and a legacy of Germany's "guest worker" programme of the 1960s and 70s.
Germany, which now believes Erdogan is effectively holding about a dozen of its citizens hostage, last month announced a full review of relations and sharpened its travel advisory.
Erdogan's rows with Germany and other EU countries, human rights concerns and his warnings that Turkey could bring back the death penalty have put on ice its bid to join the European Union, which Berlin has suggested should end.
The tensions also threaten a controversial EU-Ankara refugee deal from 2016 that helped drastically reduce the mass influx of refugees and migrants, more than one million of whom ended up in Germany.
Here are five flashpoint issues that have, step by step, sped up the downward spiral in German-Turkish relations.
Turkey is holding the correspondent of Die Welt daily, Turkish-German Deniz Yucel, on terror charges and has also detained other journalists and rights activists, including Peter Steudtner.
Dogan Akhanli, a German writer of Turkish origin, is now fighting extradition to Turkey from Spain.
Free speech issues have for years weighed on relations. Turkey ranks 155th on the latest Reporters Without Borders world press freedom index.
In March 2016, German TV comedian Jan Boehmermann infuriated Erdogan with his satirical "Defamatory Poem" in which he gleefully and crudely accused him of bestiality and watching child pornography, sparking a deep row and lengthy court battles.
Amid the tensions, Germany's parliament in a June 2016 vote joined more than 20 other countries in labelling the Ottomans' World War I-era massacre of Armenians a "genocide".
A furious Erdogan accused German lawmakers of Turkish origin of having "tainted blood", and several remain under special police guard after receiving anonymous death threats.
Armenians say that 1.5 million of their people were killed by Ottoman forces from 1915 in the first genocide of the 20th century. But Turkey vehemently rejects any use of the word genocide saying that up to 500,000 died when Armenians rose up and sided with invading Russian troops in World War I.
Chancellor Angela Merkel's spokesman only defused the row by clarifying that the resolution was "not legally binding".
For months after the Armenia vote, Turkey denied Bundestag lawmakers the right to visit 250 German troops then stationed at the Incirlik NATO base near Syria.
Germany has been flying Tornado surveillance missions over Syria and otherwise supported partner nations battling the Islamic State jihadist group.
After the issue flared again this year, Germany in June withdrew the contingent, moving it to Jordan's Azraq base.
On July 15, 2016, a Turkish renegade army faction attempted a coup against Erdogan which left almost 250 people dead, not including the plotters.
Erdogan blamed US-based cleric Fethullah Gulen, a former ally turned arch-foe.
Since then 50,000 people have been arrested and more than 100,000 fired or suspended from their jobs, among them soldiers, police, magistrates and journalists, sparking international controversy.
Erdogan has accused Germany of sheltering plotters, as well as Kurdish militants, and demanded their extradition.
Germany says Turkey's MIT secret service and state-linked imams have been spying on Gulen followers in Germany.
Turkish politicians have long sought to rally Turkish voters in Germany, but tensions rose after the coup and ahead of the April 16 referendum on expanding Erdogan's powers, which narrowly passed.
Several German towns barred rallies by pro-Erdogan politicians, sparking vitriolic exchanges in which Erdogan accused Germany and the Netherlands of behaving like "Nazis".
With Germany now in campaign mode ahead of September 24 elections, Erdogan has urged Turks in Germany to vote against Merkel's conservatives and other "enemies of Turkey".
The German foreign and justice ministers warned Erdogan was using "propaganda" to divide the Turkish community, threatening the democratic culture of Germany.