Often the name Johannis was the official name and Jan the proper one for daily use.
The age is not stated in this certificate so it could be Joannes Hollander or Jan Jansen Hollander .
Not in Holland as suspected but on board of H.M.S Pandora and buried in Yarmouth.
Here are the originals
The story in the family as told by Herbert B.Vlieland .
Our family was originally Dutch,but the last war between Holland and French,
in a naval battle,my great grandfather,an admiral had his ship sunk under him and was shot swimming to another ship.
His son was captain and taken prisoner".
So far his story.