To identify a specific family or clan? To use specific imagery that is UNIQUE to that family or clan? To distinguish a family or clan from others?
Is not a coat of arms by nature something that should be unique, all different from each other representing different times, places, symbols etc?
If so then how do we explain the double-headed eagle, which appears on crests and coat of arms from ALL OVER THE WORLD? How can this be? Why/how would so many cultures and empires all use this very odd symbol, of a creature that is not even known to exist?
Super interesting imo:
The examples of this symbol go on and on... they are truly countless, here is just a small sampling:
![Image](https://i.imgur.com/MZPF0KL.jpg)
![Image](http://www.ancient-origins.net/sites/default/files/field/image/Double-Headed-Eagle-Motif.jpg)
![Image](https://gravelyspeaking.files.wordpress.com/2014/01/img_7920.jpg)
![Image](http://www.ufo-contact.com/wp-content/uploads/2011/09/Hellenistic-Thracian-pin.jpeg)
![Image](https://mikemcclaughry.files.wordpress.com/2012/10/double_headed_eagle_of_the_holy_roman_empire_circa_1510.png)
![Image](https://www.slavorum.org/wp-content/uploads/2017/01/800px-Albrecht_Altdorfer_044.jpg)
![Image](http://farm4.staticflickr.com/3094/3179830173_1be144859d_z.jpg)
![Image](https://www.hittitemonuments.com/alacahoyuk/alaca08d.jpg)
![Image](https://americafarm.files.wordpress.com/2014/03/eagle-seal1.jpg?w=560)
![Image](http://tamilandvedas.files.wordpress.com/2011/12/452px-keladi_rameshwara_gandaberunda.jpg)
![Image](https://en.numista.com/catalogue/photos/serbie/g113.jpg)
![Image](https://russkieland.wordpress.com/files/2008/09/russian_eagle_large.png?w=268)
![Image](https://2.bp.blogspot.com/-ltV51MnxHWA/TsvVwYSHAlI/AAAAAAAATK8/62-zp1LMhjo/s1600/bwc_doublehe_cover.jpg)
![Image](http://erilainen.files.wordpress.com/2011/02/double-headed-eagle1.jpg)
![Image](https://biblewalks.com/Photos44/HolySepulcher39s.jpg)
![Image](https://c2.staticflickr.com/4/3160/2932335188_fe6589a5d8_z.jpg)
![Image](http://www.smileplanet.ru/upload/hl-photo/6a0/3cb/dvorsovaya_ploshad_v_peterburge_26.jpg)