i was thinking maybe the slovanic Богатйрй (Bogatyeiryei). Fight mounted or dismounted, usually with spears or swords. Records show that they used chainmail with a round-top helm with a nose-guard. Possibly some chain mail hanging off the helm to protect the neck and shoulders form blows. Nothing to protect the legs usually, but the chainmail usually hangs down to the knees. Also used a round medum-sixed shild, probably 2 feet in diameter with a metal handguard or whatever in the middle.