Since I was a just a nipper there were gamers at the Grays club using 15mm Late Roman armies for their games. This was the period of WRG 6th Edition Ancient Wargames Rules, so there was apparently a single year in the army lists where Legionaries could be armed with Pilum, dart, javelin and boomerang (probably) without the inefficient points cost of mail armour. This made for a deadly tabletop presence which was optimised for tackling pike based armies. It didn't really catch my imagination I have to admit.
It was some years later that a sort of group hysteria overcame three of us visiting the old Broadsword Show in Walthamstow. We found ourselves buying scads of the Gripping Beast Arhturian and Late Roman 28mm figures without the least plan as to how or why we were going to use them. The other two quickly came to their senses. Before I realised though I had already bought some more figures, painted a bunch and started to read up on the period.
So that was me hooked. It has remained a side project however for many years.