Thanks Doug - let me give another explanation since its confusing.
Starting in the 12th century some Knights were termed 'Knights of the Bath' when they were knighted and this became more common in the 14th century to distinguish knights who went through an elaborate ceremony vs. knights who were just 'dubbed, and because of the connection to the monarch I would consider this "an honour".
Joe's link above to Arthur Shaw book which explains this on page xv pretty succinctly and uses that term. There was no Order of the Bath at this time so they were not companions, no officers, and no membership restrictions. They only real connection to the future order is the name.
Last Knights of the Bath were created at the coronation of King Charles II in 1661. No KB between 1661 and 1725.
In 1725, King George I created the Order of the Bath, which at first only had one membership category, Knight Companion, which used the post nominal initials that I see most often in other peerage sources, K.B. In 1815 they changed the order to have a similar hierarchy as other orders of chivalry and existing members became Knight Grand Cross of the Bath (GCB).
With dates, there's three categories:
- Knights of the Bath before 1725 (really before 1662) Initials KB
- Knights Companion of the Order of the Bath 1725-1815 Initials KB
- Knights Grand Cross of the Order of the Bath 1815-present Initials GCB (also KCB, CB)
The first one I thought should just be a subcategory of Category: Honours and Awards of the United Kingdom. The second two are subcategories of the Order of the Bath, Happy to create the category but it would be nice if the UK proj or EuroAristo would manage it.