A while ago I started photographing flags because I often see some on my ways. So, I created a tag for flag photos and I do now collect them on my blog too. At the top, you can see the flag with the coat of arms of Hamburg. The colors of Hamburg are white and red. The Hamburg coat of arms always shows a castle with three towers. The tower in the middle has a cross on top and it’s believed that it stems from the fact that Hamburg was an archbishopric. You can learn more about it on Wikipedia.
Diary of Dennis 
That is interesting. The origin of flags and symbols can be quite interesting. I saw a video on YouTube about the origins of the German flag. It was interesting how it originated and changed over the years.
Yes, vexillology and heraldry are quite interesting. I don’t know the history of all flags or coat of arms, but over the years, I’ve read quite a lot of articles on Wikipedia about different flags I was curious about.
Yes, the modern-day German flag originates from the time 1918 to 1933 and the Weimar Republic. It’s an interesting topic too. The history of the Reichsadler goes far beyond that, back to the Holy Roman Empire, except that we have a one-headed eagle in the flag today and not a two-headed eagle.
Sometimes I see the eagle on the flag and sometimes I do not see the eagle. Which is the official flag today?
The one without the eagle. The one with the eagle is the service flag or basically the flag of the German federal authorities and may only be used by the authorities. But honestly, even if people could get a fine for doing so, I can’t tell you how often I’ve seen citizens raising that flag in their gardens too. Or during football world championship or euro cups, it’s apparent too. But yeah, strictly speaking, the one with the eagle can only be used by the government bodies, and the one without the eagle is the official national flag that can be used by everyone.
So, to explain further, internationally, like in the example when the flag gets raised in Brüssel together with the other EU member states… you’d see the flag without eagle raised there, because it’s our official flag. But if you’d see a motorboat of the German federal police, it’ll have the flag with the eagle on the boat. Or another example where the service flag would be used is at the German embassy. I think that should explain it.