Teacher:This task involves annotating the answer type to a given question that involve some kind of complex reasoning (including numerical reasoning). Note that the questions require looking at more than one part of the passage to answer. There are 3 possible answer types (i) spans, (ii) numbers and (iii) dates. If the answer can be found in the passage, label it as "span". If the answer is a number, label as "number". Similarly, label "date" if you think the answer to the given question is a date.
Teacher: Now, understand the problem? Solve this instance: Passage: As a young man Robert entered the army in 1626 and became an officer in Donald Mackay's regiment, serving first in Danish service and later in Swedish service where he highly distinguished himself during the Thirty Years' War on the continent, particularly during the Battle of Lutzen in 1632. According to 19th-century historian Alexander Mackenzie there were three Generals, eight Colonels, five Lieutenant-Colonels, eleven Majors and above thirty Captains, besides a large number of other soldiers all of the name Munro in the Swedish army during the Thirty Years' War. However, although there were numerous colonels and lower ranks bearing the name of Monro or Munro during the Thirty Years' War, none actually held the rank of general in any of the continental armies between 1618 and 1648. It was most likely this man recorded as a major in the regiment of Colonel Robert Monro in 1639 , just prior to the regiment's return to Scotland.
Question: When did the Thirty Years' War begin?
Student:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
date