The Sultans

It may be a bit late in the story to explain this, nonetheless, here goes. Once upon a time there was the very first Sultan, names Osman the 1st. He didn't have much to leave as an inhertiance to his son, just some herds a sword and some land. He also couldn't read or write. But he needed to to make a signature, so instead of signing he dipped his hand in ink and places it as a seal. However, his pinky finger didn't press.

With the second Sultan, Orhan the 1st, there was the beginning of the Tughra, or calligraphic seal, based upon the design of the Sultan's first imprint (if you look you can see the form of a thumb to the left, three fingers and a palm). From Orhan on to the end of the Ottoman Sultans, this same design was used, just modified with the name of each successor.

Here is a break down of the parts coutesy of Wikipedia.