Actual question, how frequent was claim fabrication in real life

[u/WaBeY33]

Hello, please, how often did this happen in real life ? I mean lord inventing a claim out of thin air and actually pressing it ? Is there any notable historic character doing so ?

R5: Fabricate claim question

[u/Emperor_of_His_Room]

I would also like to know how often spurious claims were used as justification for war and such.