The outspoken bank boss, who has the unenviable task of trying to reform the lumbering giant that is Deutsche, posted a statement a statement on its website saying this is "not such a good day for Europe".
The post read:
I’m afraid that this is not such a good day for Europe. At this stage, we cannot fully foresee the consequences, but there’s no doubt that they will be negative on all sides.
As a bank headquartered in Germany and with a strong presence in the UK, we are well prepared. However, there’s no doubt that the uncertainty created by the referendum’s results will be a challenge.
Let me add a personal note: I am a strong supporter of the European project, which has brought peace and prosperity for more than 50 years.
As a Briton and a European, it especially saddens me that Europe has obviously lost its attractiveness for many of my fellow countrymen. It’s a clear signal to the EU to get closer to its people and to strengthen democracy.