Space Viking by H. Beam Piper

A dozen men clustered around the bartending robot -- his cousin and family lawyer, Nikkolay Trask; Lothar Ffayle, the banker; Alex Gorram, the shipbuilder, and his son Basil; Baron Rathmore; more of the Wardshaven nobles whom he knew only distantly. And Otto Harkaman.

Harkaman was a Space Viking. That would have set him apart, even if he hadn't topped the tallest of them by a head. He wore a short black jacket, heavily gold-braided, and black trousers inside ankle-boots; the dagger on his belt was no mere dress-ornament. His tousled red-brown hair was long enough to furnish extra padding in a combat-helmet, and his beard was cut square at the bottom.