---
title: "Mercenaries — AP European History Definition & Exam Guide"
description: "Mercenaries were hired professional soldiers who dominated European warfare 1500-1648, before standing armies. Key for AP Euro Unit 2 and warfare-change LEQs."
canonical: "https://fiveable.me/ap-euro/key-terms/mercenaries"
type: "key-term"
subject: "AP European History"
unit: "Unit 2"
---

# Mercenaries — AP European History Definition & Exam Guide

## Definition

Mercenaries were professional soldiers hired for pay rather than loyalty, and they did most of the fighting in European wars from roughly 1500 to 1648, before centralized states built permanent standing armies under their own control.

## What It Is

Mercenaries were soldiers for hire. Rulers in the 16th and early 17th centuries usually didn't have permanent national armies, so when war broke out they paid military contractors to recruit, equip, and lead troops who fought for money, not for king or country. Famous examples include the Swiss pikemen and German *Landsknechte* who filled out the armies of rulers like [Charles V](/ap-euro/key-terms/charles-v "fv-autolink").

This system had a built-in problem. Mercenaries fought as long as the pay showed up. When it didn't, they mutinied, deserted, or plundered the nearest town (unpaid imperial troops infamously sacked Rome itself in 1527). During the [religious wars](/ap-euro/key-terms/religious-wars "fv-autolink") of [Unit 2](/ap-euro/unit-2 "fv-autolink"), mercenary armies living off the land devastated civilian populations, which is part of why the Thirty Years' War was so destructive. That destructiveness, plus the unreliability, pushed states after 1648 toward professional standing armies that were paid, drilled, and controlled directly by the central government.

## Why It Matters

Mercenaries sit in **Topic 2.6, 16th-Century Society & Politics in Europe (Unit 2: Age of [Reformation](/ap-euro/key-terms/protestant-reformation "fv-autolink"))** and support learning objective **[AP Euro](/ap-euro "fv-autolink") 2.6.A**, which asks you to explain how economic developments from 1450 to 1648 reshaped social structures and politics. Hiring armies cost enormous amounts of money, so the mercenary system tied warfare directly to state finance. Rulers had to tax more, borrow from bankers, and build bureaucracies to pay for war, which fed the long-term growth of centralized states. Mercenaries are also your best 'before' picture in the AP Euro story of military change. The shift from hired contractors to state-controlled standing armies is one of the clearest continuity-and-change arguments in the whole course.

## Connections

### [Charles V (Unit 2)](/ap-euro/key-terms/charles-v)

Charles V's wars against France and the Protestant princes ran on mercenary armies, and the costs nearly bankrupted him. His unpaid troops sacking Rome in 1527 is the classic example of why hired soldiers were a risky tool.

### Wars of Religion (Unit 2)

Mercenaries didn't care about theology. Catholic soldiers fought for Protestant paymasters and vice versa, and armies that lived off the land made conflicts like [the Thirty Years' War](/ap-euro/key-terms/the-thirty-years-war "fv-autolink") catastrophic for civilians.

### Absolutism and standing armies (Unit 3)

Absolutist monarchs like [Louis XIV](/ap-euro/key-terms/louis-xiv "fv-autolink") replaced hired contractors with permanent, state-funded armies loyal to the crown. If you understand mercenaries, you understand exactly what the standing army was invented to fix.

### [Estates system (Unit 2)](/ap-euro/key-terms/estates-system)

Mercenary warfare chipped away at the old social order. When states could buy military power instead of relying on noble knights, the [nobility](/ap-euro/key-terms/nobility "fv-autolink")'s traditional role as the warrior class started losing its justification.

## On the AP Exam

Mercenaries show up most powerfully in continuity-and-change essays about warfare and state power. The 2017 LEQ (Question 2) asked for a significant similarity and difference between how European states waged war circa 1500-1648 and in a later period, and mercenaries are the obvious evidence for the earlier era. The argument writes itself. States in 1500-1648 rented their armies; states afterward owned them. In multiple choice, expect mercenaries in stems about the costs of war, the sack of Rome, the devastation of the Thirty Years' War, or why rulers needed new taxes and loans. Your job is to use the term as evidence of how warfare drove state centralization, not just to define it.

## mercenaries vs Standing armies

Mercenaries were temporary hired contractors who served whoever paid them and disbanded (or rampaged) when the money ran out. Standing armies were permanent forces recruited, paid, and controlled year-round by the state itself, a hallmark of later absolutist monarchies like Louis XIV's France. The shift from one to the other is a core change-over-time argument in AP Euro, so don't use the terms interchangeably.

## Key Takeaways

- Mercenaries were professional soldiers hired for pay, and they did most of the fighting in European wars between roughly 1500 and 1648.
- Because mercenaries fought for money rather than loyalty, they mutinied or plundered when pay stopped, as in the sack of Rome by Charles V's unpaid troops in 1527.
- Paying for mercenary armies was so expensive that it forced rulers to raise taxes, borrow heavily, and build bureaucracies, fueling the growth of centralized states.
- Mercenary armies living off the land made the religious wars, especially the Thirty Years' War, devastating for civilian populations.
- After 1648, states increasingly replaced mercenaries with standing armies under direct royal control, a key marker of absolutism in Unit 3.
- On the exam, mercenaries work best as 'before' evidence in continuity-and-change essays about how European states waged war.

## FAQs

### What were mercenaries in AP Euro?

Mercenaries were professional soldiers hired by rulers to fight for pay rather than national or religious loyalty. They dominated European warfare from about 1500 to 1648, before states built permanent standing armies.

### Did mercenaries fight for their religion during the Wars of Religion?

No. Mercenaries fought for whoever paid them, so Catholic soldiers regularly served Protestant employers and vice versa. That's a great detail for showing the religious wars were also about money and power, not just faith.

### How are mercenaries different from a standing army?

Mercenaries were temporary contractors hired per war and loyal only to their paycheck. A standing army is a permanent force funded and controlled directly by the state, like Louis XIV's army in Unit 3. The transition between the two is the big change AP Euro wants you to explain.

### Why did European states stop using mercenaries?

Mercenaries were unreliable and destructive. They mutinied when unpaid (the 1527 sack of Rome) and devastated civilians during the Thirty Years' War. After 1648, monarchs increasingly built standing armies they could actually control.

### Is the term mercenaries actually on the AP Euro exam?

Yes, it appears in real exam contexts. The 2017 LEQ asked how European states waged war circa 1500-1648 compared to a later period, and mercenary armies are the core evidence for the earlier era.

## Related Study Guides

- [2.6 16th-Century Society & Politics in Europe](/ap-euro/unit-2/16th-century-society-politics/study-guide/CTBpUqc1dV9ft0NFBv4v)

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