A hat as a landing site for a bird of paradise. This extraordinary headdress was worn by wealthy women in the early 19th century, one assumes to draw attention to themselves. Might the preserved exotic bird transfer its beauty to the wearer?

Even under a fabric camouflage, the characteristic shape of the German spiked helmet, or "Pickelhaube," remains unmistakable. It remained a purely military accessory before it was adapted by police and even firefighters. Most often associated with Prussian soldiers whose uniform the helmet belonged to from the middle of the 19th century, the spiked helmet was famously worn by Otto von Bismarck.

This pink handmade hat with cat-like ears, dubbed the pussyhat, was created to be worn by hundreds of thousands of women taking part in the "Women's March" that happened across the US and the world in March 2017 to protest against the misogyny of the newly elected US President, Donald Trump. The hat has since became a feminist trademark in the #MeToo age.

Respirators are also a special type of headgear. Soldiers wore them in the First and Second World Wars to survive poison gas attacks, a new insidious form of warfare that has thankfully since been banned. But these days masks, if not quite respirators, are commonly used by people living in highly polluted cities.

To oppose the ban on teaching students while wearing a headscarf, Fereshta Ludin went to the Federal Constitutional Court in Karlsruhe in 2003 but lost her case. The dispute over the headscarf ban divided Germany. The "Hat's off" exhibition at the Stuttgart House of History in Baden-Württemberg is advocating for more tolerance, no matter what one chooses to wear on their head.