[Victrix]

I’m not sure estocs were designed to penetrate plate armour but they look like they could be used to stab any vulnerable gaps in the armour. Estocs were more likely designed specifically to penetrate chain mail. The sharp narrow tip would enter a chink in the mail and then the momentum from the charging rider would force the tapering blade through the ring and expand this until it burst and enabling the blade to penetrate deeper. I believe sometimes the estoc would be held against the side when charging, in which case it would be used a bit like a lance. The tulwar above looks like that although the tip doesn’t look very sharp.

Estocs were used well into the 18thC in E.Europe because the Ottomans continued to use chainmail until quite late, probably because they and the Persians continued to use bow and arrow. Chainmail protects against arrows but not bullets I believe. So the Hungarian and Polish hussars would carry an estoc strapped to the side of the saddle in addition to their sabre personal side arm, as Jim showed above (and see attached picture).

I also attach two pictures from the Imperial Armoury in Vienna. The first shows a knight in armour with what appears to be a huge estoc (?) two-hand sword strapped to the saddle under the leg. The other picture shows some interesting Turkish estocs, as worn by Sipahis, with what appears to be characteristic hilts. A description at the museum explicitly mentions that these swords were designed to penetrate chinks in chainmail.