When a hereditary peerage had a situation where there were no heirs, did the title always go on hold after the last person's demise?
Or could the monarch confer the title immediately on anyone?
Was it required that the individual be of the nobility or could the title go to a commoner?
Assuming it is male-to-male only then its clear when there are no heirs and the title reverts to the crown, after which it can be bestowed almost immediately.
If descent through the female line is allowed, it is more complicated but do not forget that each new monarch reissues letters patent for all existing titles of nobility, or if not actually they do in theory. Thus if a title has gone into abeyance, there is nothing preventing a new monarch issuing it to a new holder, whether or not there may turn out to be some heirs somewhere sometime.
If a title is not granted to someone else, it is possible for an heir coming forward to claim it after many generations, again though at the monarch's agreement. The Courtenay Earls of Devon did this, despite there being a Duke of Devonshire at the same time.
Claims go down ad infinitum to the legal extent allowed by the initial grant, but it is always up to the reigning monarch to recognise them.
Best Regards
Grey Wolf