How did kings ensure the baby their queen gave birth to was theirs?

Question

wouldn't it be possible she had a lover noone knew about?

Answer 1

Adultery in older times was treason to the King.

Execution was a disincentive to fool around with the Queen, but some did.

Answer 2

They couldn't.

Answer 3

There were things called chastity belts which basically was a metal belt that prevented penetration of the female parts and was opened with a lock and key.

I believe that when Prince William was born the long-standing tradition that certain royal attendance be present to insure that that baby was that of the Queen or the consort was abolished.

Answer 4

There was little gurantee unless the woman was kept guarded 24/7.  There is a myth about chastity belts being created to keep the woman faithful, in fact such devices were almost certainly anti rape deefences controlled by the women who wore them. Interestingly, Judaism recognised a long time ago that the only 100% proof of parenthood was the woman and this is the reason that (aside from non-jews permitted to enter the faith) to be jewish your mother has to have been jewish.   Even today there are scurrilous rumours that prince harry is not Chalrle's son since he has the reddish hair of Major Hewitt with wohm the late Dianna had an affair.  (In fact the reddish hair is a Spencer trait and as Harry gets older his appearance is not that disimilar to the Windsors)

Answer 5

They didn't.  Look at Princess Di's youngest son he looks just like her body guard, and it was known she fooled around.  So in the medievle times I am sure there were times when the blood line was not so pure.