Sengoku daimyo (Japanese territorial lord in the Sengoku period) Takeda clan's license with a seal was created in the era of Nobutora, and during the era of Harunobu (Shingen) license with a read seal with a dragon engraved was created and established as a family symbol.
戦国大名武田氏の印判状は信虎期に創始され、晴信（信玄）期に竜朱印状が創始され家印として定着た。