yes it existed

https://www.youtube.com/watch?v=jiu0LPeLQPE

A short and very interesting video. Apparently its better than satellite and cable HD broadcasts.

It's sounds odd and sounds impossible to have HD on VHS, but it did happen. There's no reason it couldn't be done. The media doesn't determine the picture quality.
In the same way they put digital audio onto tape, the DAT and DCC platforms.
I do think tho that a general problem with digital content on any magnetic tape would be that any tiny drop out on the magnetic medium would result in a data error, missing frames in the picture, frozen images, jumping audio and so on. That said, Optical discs such as cd, DVD, bluray can suffer in a similar way due to dust, finger prints, and scratches.

Fascinating, I remember us having a JVC DVHS machine at work on approval which I don't think was HD, no idea what happened to it.

I know that they had digital video on tapes as in video 8 but never HD until the vid came up in my subs the other day.

There was also a format called W-VHS that could record in almost HD quality or two SD programmes at the same time (or 3D).

No, it was just SD - and a complete flop

I recall my company using a US import D-VHS (D-Theater) machine for a projector launch we did at the BFI cinema in the early 2000's. The signal format was 1080i and at the time it I thought it represented the only domestic native HD format available, albeit in the US (and possibly Japan?) only at that time. Later on I found out about Muse LaserDisc players which had been available in Japan since the mid-90's, but they're pretty rare too.

Link to DVE calibration title available in D-VHS (D-Theater) format @ 1080i/60

Mini HDV was another tape based and reasonably popular format..... tape seems so very old nowadays!