By 1626 the Polish-Swedish War — really the latest round of a dynastic dispute that had been running since the 1590s — had pivoted to the Baltic provinces. King Gustavus Adolphus of Sweden had spent 1625 sweeping through Livonia and was now in Prussia trying to force a decision against his cousin Sigismund III Vasa. The defense of Livonia he handed to Jacob De la Gardie and the harder-edged field commander Gustav Horn, the count whose later campaigns would carry him to Germany and the Thirty Years' War. Aleksander Gosiewski, the Polish-Lithuanian field commander operating against them, was an experienced soldier who had spent the autumn maneuvering for any opening. When he learned Horn had stopped for the night at Drobbusch with cavalry sleeping outside the village, he saw his moment.

Gosiewski's plan was simple: hit the village from the roads at dawn, before the Swedes could recover the situation. About fifteen hundred Lithuanian troops moved into position overnight, the cavalry staying back, the assault parties pushing forward. As the eastern sky paled on 3 December, the Lithuanian columns came down the village roads at speed. They met something they had not counted on — Swedish sentries. The forward pickets fought just long enough to let officers inside the village pull men out of houses, snatch up muskets, and form a line of resistance at the edges of Drobbusch. Two banners of Cossack-style cavalry tried to slip through the woods on a flanking move, looking for the unprotected rear of the Swedish position, but ran into a detachment of musketeers and were stopped. Hand-to-hand fighting in the cottages and yards lasted long enough for Horn to begin organizing a counter-stroke.

Horn understood that as long as the Lithuanian cavalry blocked the open ground beyond the village, his own cavalry — still stranded in the woods — could not get into the fight. So he led musketeers forward himself, pushing the Lithuanian horsemen off their commanding ground. With that pressure removed, Swedish cavalry began streaming out of the trees. A single squadron of Finnish horse — Sweden's finest light cavalry — formed up and charged. According to letters Horn and Gabriel De la Gardie wrote to the chancellor Axel Oxenstierna, that one squadron broke five squadrons of Polish-Lithuanian winged hussars in the open ground and captured four of their banners. The hussars were the finest cavalry in Europe; for a single Finnish squadron to rout five of theirs is the kind of claim that demands skepticism. But the Lithuanians did break, and the rest of Gosiewski's force came apart soon after. Swedish casualties were light. Lithuanian losses came to four hundred dead, forty captured, and eight banners lost.

Horn stayed at Drobbusch for two days, gathering supplies, then moved south to push Gosiewski out of Livonia and into Courland. Here the bitter Latvian winter became the more dangerous enemy. After Gosiewski crossed the Düna (Daugava) at Yxkull, De la Gardie and Horn had to call off the pursuit. Their men were dying of frostbite and sickness in inadequate winter clothing. Horn assembled a small mobile column of three hundred cavalry and two hundred musketeers and pushed west of the river Ewst, hoping to clear out remaining Lithuanian positions. He intercepted three banners of Cossack-style cavalry escorting Gosiewski's baggage and artillery. The Cossacks fought with great bravery, lost about seventy men, and managed to push their wagons through — though they had to abandon the cannons when the roads gave out. Horn took the small post of Berson but found Laudon too strongly held. The winter campaign of 1626-1627 ended there.

Wenden — modern Cēsis in northern Latvia — has a remarkable medieval castle, built by the Livonian Order beginning in the early thirteenth century and still standing in evocative ruin today, with intact towers and partially restored interiors. The town below it is one of the prettiest in Latvia, a small grid of low painted houses around a central square, surrounded by the rolling birch and pine forests of the Gauja National Park. The exact site of Drobbusch and the 1626 fight is no longer marked, but the wider landscape is still recognizable: a country of low ridges, lakes, marshy hollows, and stands of forest where cavalry could be lost in shadow until dawn revealed them.