The UK Arms and Kings of Scots Arms have unicorn as supporters, derived from the gift of Jane Beaufort to James 1 in 1424 of the Cymric yale goat.
John of Lancaster flew it in France 1422, and Henry VII flew it with Yddraig Goch dragon in 1485 to seize the crown of England. The yale-goat with lion hindquarters is sculpted upon St.Geoge's chapel Windsor for the dragon ritual of Knights of Garter. The unicorn with swivelling horns to replace the forward horn if damaged in battle, is a goat-lion in heraldry.
"Yale" is from Assyrian "ia`ilu" ("to ascend") wild ibex, Hebrew "yael", Hindi "yali" deer with swivelling horns.
The Red Dragon is said to derive from Roman dragon-banners. The Roman flag in Koblenz Museum is in snake form, L.draco, Gk.drakon "snake". This horned snake wyvern/guivre/ viper is held by Cernunnos deer-horned god on Gundestrup Cauldron, from Thrace north Greece, home of Ares ram war-god of Thrace. The military symbol of Macedonia was the unicorn, carved at Persepolis, Persia after Greek-Macedonian defeat.
Homer,Herodotus, Diodorus Siculus and Alcman of Sparta wrote on Celtic ancestor legend. Brettanos of Gaul was father of Echidna (viper) Kelto dragon snake-woman, who was mother of Chimera (Gk. chimaira "goat")
a goat-lion war-goddess who battled Bellerophon on Pegasus horse.
The dragon and yale-goat battle-symbols of Celts go back 3000 years.