Stålarm's temporary release in 1602 was due to difficulties Charles encountered in his war against Poland–Lithuania in the Duchy of Livonia. There, Charles had attracted the renowned John of Nassau to command his forces in July 1601. John began to re-organize the Swedish forces in Livonia according to the Dutch model, but due to shortages in equipment, numbers and other problems he gave up and left for Holland in the summer of 1602. He left behind an army reduced to the Livonian strongholds of Dorpat (Tartu) and Pernau (Pärnu) and even losing ground in famine-plagued Swedish Estonia, which Michal Roberts described as follows: "The Dutch tactics were worse than useless—indeed, they were positively dangerous—as long as the men had an inferior firearm and no pike-hedge behind which they could take cover. [...] The army had been half-reformed, and the last state of it was arguably worse than the first." Charles then released Stålarm from prison to take over John of Nasau's command.