There is plenty of evidence that trained duelists and sword fighters during the 17th century until at least the late 18th Century wielded both a dagger (poignard) and sword.

There are plenty of sources for people carrying two loaded pistols in the late eighteenth and early nineteenth century. When you've only got the one shot per pistol with a flintlock it makes sense to have more than one (for visual intimidation as much as anything else one assumes) pistol to hand. Use of sword/cutlass and pistol during naval engagements are also numerous.

Earlier? I've no sources to hand.

Alexei Potapov talks in his book "Handgun Shooting Methods: The SMERSh system", FAIR-press, Moscow, 2002 about shooting with two revolvers and later two pistols as the "macedonian way". Which presumably was shown to NKVD officers as soon as 1944.

I found a forum post containing a little excerpt because I can't access the book here and I have read it ages ago.

In the mid-16th century, a German mercenary cavalry force called the Schwarzreiters or Black Knights were hired into French armies. They were armed with two wheellock pistols and a sword, and their signature tactic was the caracole. A squadron of men would charge at the enemy, then at close range the front rank would fire their pistols and immediately peel off to head to the back of the formation to reload, while the second rank was in the act of firing.

This tactic of 'rolling volleys' of pistol fire wasn't very effective because of the inherent inaccuracy that comes with firing a pistol from a full gallop. In fact, what tended to happen was that the second or third ranks would fire preemptively into the air instead of waiting to be in front of the enemy. However, its shock value was undeniable, leading to a contemporary report that a battlefield witness could "see only fire and steel." Furthermore, the idea of closely-packed heavy cavalry was adopted from the Reiters and used to great effect in the future.

Source: Ronald Love, "All the King's Horsemen": The Equestrian Army of Henri IV, 1585-1598. The Sixteenth Century Journal, Vol. 22 No. 3, Autumn 1991