[Timo Nieminen]

Some candidates for late Medieval knives with integral bolsters:
http://finds.org.uk/database/artefacts/record/id/86821
http://finds.org.uk/database/artefacts/record/id/86819
http://finds.org.uk/database/artefacts/record/id/86817
http://finds.org.uk/database/artefacts/record/id/86808

According to Paul Binns, integral bolsters appear in early Tudor. An iron tang is welded on to a steel blade on these, and the bolster is formed from the join: http://www.paul-binns-swords.co.uk/knives.html