Battle of Jankau

Background

By the winter of 1644–45 the Emperor Ferdinand III was running out of armies. Peace talks had opened in Westphalia in 1643, but Ferdinand had stalled them in the hope that a successful 1644 campaign would improve his terms. Instead the Swedes under Field Marshal Lennart Torstensson beat the Danes and then ruined Matthias Gallas's Imperial army in Saxony; Gallas fell back into Austrian territory with his army reduced, by the 1911 Britannica's count, from 20,000 men to 2,000.

Torstensson, though crippled by gout, proposed a three-part offensive for 1645. France would attack Bavaria; he would invade Bohemia and join forces with George Rákóczi, Prince of Transylvania, then in revolt against the Emperor; and the combined armies would march on Vienna.

With Rákóczi tying down troops in Hungary, Ferdinand turned to Melchior von Hatzfeldt to rebuild an army around his own corps and the wreck of Gallas's. Johann von Götzen was recalled from Hungary to join him, and Maximilian of Bavaria sent Johann von Werth with his cavalry. Torstensson crossed the Ore Mountains into Bohemia in late January, hauling his guns on sledges over the frozen ground. For three weeks the two armies shadowed each other along the Vltava (Moldau) while Hatzfeldt covered Prague. A hard frost let the Swedes cross the river in early March and swing east towards Moravia and the road to Vienna. Hatzfeldt marched faster, reached Tábor on 4 March and on 5 March took up a blocking position in the wooded hills around Jankov (Jankau), about 60 km south-east of Prague, roughly halfway between Votice and Louňovice pod Blaníkem.

The armies

The two armies were much the same size, about 15,000–17,000 men each, but differently built. The Swedes had perhaps 6,000 foot and 9,000 horse and a powerful artillery train of about 60 guns, most of them light 3-pounders. The Imperial army had perhaps 4,500–5,000 foot and 10,000–10,500 horse but only 26 guns; its heavier pieces had been left behind.

Torstensson's army was a single, well-integrated force of long-serving regiments under a commander it trusted, with capable subordinates: Arvid Wittenberg, Robert Douglas, Mortaigne de Potelles and the cavalry commander Johan Arnold von Goldstein. The young Charles Gustav, later King Charles X of Sweden, rode with it.

Hatzfeldt's army was a coalition of three. Many of the Imperial regiments were poorly equipped remnants of earlier defeats, and Hatzfeldt could not control his two seconds. Götzen, a hard-drinking veteran, commanded one wing of horse; Werth, the most famous cavalry leader on the Catholic side, brought the Bavarian contingent, mostly veteran cavalry. Hatzfeldt's own name was already linked with the defeat at Wittstock. The Imperial advantage lay in its numerous horse; the Swedish advantage lay in its infantry, its guns and its command.

The battle

CDB90 records Jankau as a single engagement, number 16 (JANKAU), covering the whole of 6 March 1645. Times below follow Swedish Wikipedia's account and English Wikipedia's, which draws on Wilson; the two differ in places, and the order of some episodes is uncertain.

5 March: the position. Hatzfeldt chose strong ground. His line ran along a long wooded ridge near Jankov. Hills and woods would blunt the Swedish guns, a stream covered his centre and a steep, wooded slope his right. His left was weaker: open ground lay in front of it, overlooked from the south by a height crowned by a chapel, which English accounts call Chapel Hill. A belt of ponds and a narrow, wooded ravine lay between it and the Imperial left. The Swedes camped in the hills to the north-west, and Torstensson reconnoitred the ground himself.

06:00–09:30: Chapel Hill and Götzen's attack. At about 06:00 the Swedes moved off in three columns. Douglas made a feint against the Imperial right while the main body marched round the Imperial left towards Chapel Hill, the frozen ground letting them drag their guns onto the crest. Hatzfeldt rode to watch the feint, leaving Götzen orders to hold the hill. Götzen instead took the whole wing forward through the woods and ponds. His cuirassiers jammed in the ravine under the Swedish guns on Chapel Hill and were cut up, and a Swedish counter-attack drove the survivors back into the forest. Götzen was killed, by English Wikipedia's account just after 09:15. Imperial infantry and guns moving up to support the left met Swedish foot in the woods; Wittenberg took the guns stuck in the mud.

Mid-morning: the Swedes envelop the line. Two Swedish brigades under Mortaigne and Seestedt pushed on too early and were struck by Werth's Bavarian horse; Seestedt was killed and 13 standards lost before Swedish guns steadied the line. Torstensson then moved his cavalry and his main battery onto a ridge between the villages of Podol and Wodlochowitz, overlapping the Imperial position, and Hatzfeldt ordered a withdrawal. The armies broke contact just before midday.

Noon–14:00: the Imperial counter-stroke. Judging the Swedes too close for a safe retreat, Hatzfeldt stood his ground on a ridge where his musketeers were digging in. The Swedes took the position and Hatzfeldt retook it. On the Imperial right, Douglas massed three squadrons into one and charged Bruay's brigade; Bruay was mortally wounded and taken. Werth then struck the Swedish right near Ratměřice (Radmeritz) before it had finished deploying, broke through to the artillery and the baggage, and stopped to plunder. Torstensson's wife, Beata De la Gardie, was briefly taken before Swedish horse freed her.

14:00–16:00: the collapse. The pause let the Swedes rally. Torstensson brought his guns forward onto the hills south-west of Ratměřice and fired into the Imperial foot at close range, scattering the Bavarian cavalry. Imperial cuirassiers who came through the wood against the Swedish infantry were destroyed by the reserves, the Swedish counter-attack broke the Imperial infantry, and much of it surrendered. Hatzfeldt, with a few followers, tried to escape into a wood and was taken by two Swedish NCOs at about 16:00.

Aftermath

The Imperial army was destroyed as a field force. It lost about 4,000 killed and wounded and some 4,450–4,600 prisoners, among them Hatzfeldt, five other generals and over 200 officers, together with all its guns. Götzen, Bruay and Colonel Philipp von Waldeck were dead. Of 36 regiments, only 2,697 men had reached Prague a week later. Of Werth's Bavarian cavalry only 1,500 returned to Munich. Swedish losses were perhaps 1,500–4,000.

Ferdinand left Prague for Vienna. Within a month the Swedes had taken Krems and Korneuburg and reached the Danube before Vienna. But Bohemia and Moravia were too wasted to feed them, Rákóczi came late and then made his own peace, and Torstensson's siege of Brno, held by de Souches, failed after more than three months. By October he had fewer than 10,000 men; in December he handed command to Carl Gustaf Wrangel.

The larger effects were political. Saxony, unprotected, made a truce with Sweden at Kötzschenbroda in September 1645, and Ferdinand ordered his envoys at Münster and Osnabrück to negotiate in earnest, the road that led to the Peace of Westphalia in 1648. Peter Englund compares the blow to that of Rocroi to Spain. Arguments turn on blame: Hatzfeldt blamed Werth, and later writers have blamed Götzen's rash attack or Hatzfeldt's failure to impose control on his subordinates. A memorial was raised near Jankov in 1995, and Czechs still say a man who has come to grief has fared 'like Götz at Jankov'.

Wargaming it

Jankau is a mid-sized pike-and-shot battle, about 16,000 a side, which makes it manageable at a regiment or squadron scale with 20–30 minute turns, or at a larger brigade scale in an evening. It is unusual for the period: a manoeuvre battle fought across broken, wooded hills and frozen ponds rather than two lines facing each other on open ground.

The key terrain is Chapel Hill on the Imperial left, the ponds and ravine below it, the woods that split the Imperial army in two, and the ridges near Ratměřice where Torstensson placed his batteries. Woods and ponds should break up cavalry and slow guns badly, so the light Swedish 3-pounders that can move with the foot become a real asset.

The game rewards command rules. The Imperial player has more and better horse but three quarrelling commanders; random or limited initiative for Götzen and Werth, or a chance that Werth's troopers loot the baggage, recreates the problem. The Swedish player has one commander, more guns and better infantry, and must take Chapel Hill before the Imperialists can react.

What ifs: Götzen holds the hill instead of attacking; Hatzfeldt retreats at midday instead of standing; Werth's cavalry rally on the Swedish guns instead of the wagons. A two-part scenario, morning and afternoon, works well.

Maps and pictures