The statement which attributes the lessening of the baronage to the Wars of the Roses seems indeed to be an error.

Although Henry the Seventh, in dread of opposition to his throne, summoned only a portion of the temporal peers to his first Parliament, there were as many barons at his accession as at the accession of Henry the Sixth.

Of the greater houses only those of Beaufort and Tiptoft were extinguished by the civil war.

The decline of the baronage, the extinction of the greater families, the break-up of the great estates, had in fact been going on throughout the reign of the Edwards; and it was after Agincourt that the number of temporal peers sank to its lowest ebb.
From that time till the time of the Tudors they numbered but fifty-two.

A reduction in the numbers of the baronage however might have been more than compensated by the concentration of great estates in the hands of the houses that survived.