Deception and Double Agents: The Success of Operation Fortitude

Guiding Question:

How did the success of Operation Fortitude contribute to the success of Operation Overlord?


Operation Fortitude was essential to the success of Operation Overlord and the Normandy Invasion. This lesson explores the reasons behind the success of Operation Fortitude, why this operation was so successful, and how this major deception was planned and executed. Students will learn the reasons for and the necessity of Operation Fortitude, use critical thinking skills to determine the impact of Fortitude, and write narratives of the events using historical evidence.


Historical Context

The Allied invasion of Normandy was the beginning of the end for the Nazi regime. Years of planning and preparation were vital to the success of D-Day, including an operation that did not include active fighting, bombs or combat. Operation Fortitude was a strategic deception put in place by the Allies to convince Hitler the invasion would occur farther down the coast at Pas-de-Calais. This operation was so successful that even after the invasion of Normandy had begun, the Nazi commanders remained convinced Normandy was a diversionary tactic and the bulk of the invasion would occur at Pas-de-Calais. This belief kept a significant number of German troops and Panzer divisions out of Normandy for the first crucial days of fighting.

Operation Fortitude involved spies, double agents planting false information, inflatable tanks, and an entire ghost army commanded by General George Patton, all staged to convince Hitler of an alternate landing site for the invasion. Without this deception, the Allies would have met even stronger resistance and had an even higher casualty rate on June 6, 1944. Cambridge American Cemetery honors many of those who lost their lives in the weeks and months before the Normandy Invasion.


At the conclusion of this lesson, students will be able to

  • Identify the importance Operation Fortitude played in the success of Operation Overlord;
  • Analyze the reasons Pas-de-Calais was the more believable point of attack; and
  • Complete a writing prompt that engages students with Operation Fortitude.

Standards Connections

Connections to Common Core
CCSS.ELA-Literacy.W.6-8.3 Write narratives to develop real or imagined experiences or events using effective technique, relevant descriptive details, and well-structured event sequences.
CCSS.ELA-Literacy.W.8.1 Write arguments to support claims with clear reasons and relevant evidence.
CCSS.ELA-LITERACY.W.8.9 Draw evidence from literary or informational texts to support analysis, reflection, and research.
CCSS.ELA-LITERACY.RH.6-8.7 Integrate visual information (e.g., in charts, graphs, photographs, videos, or maps) with other information in print and digital texts.
CCSS.ELA-LITERACY.WHST.6-8.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/ experiments, or technical processes.

Connections to C3 Framework
D2.His.1.6-8 Analyze connections among events and developments in broader historical contexts.
D2.His.3.6-8 Use questions generated about individuals and groups to analyze why they, and the developments they shaped, are seen as historically significant.
D2.His.15.6-8 Evaluate the relative influence of various causes of events and developments in the past.
D3.3.6-8 Identify evidence that draws information from multiple sources to support claims, noting evidentiary limitations.
D3.4.6-8 Develop claims and counterclaims while pointing out the strengths and limitations of both.
D4.1.6-8 Construct arguments using claims and evidence from multiple sources, while acknowledging the strengths and limitations of the arguments.
D4.3.6-8 Present adaptations of arguments and explanations on topics of interest to others to reach audiences and venues outside the classroom using print and oral technologies (e.g., posters, essays, letters, debates, speeches, reports, and maps) and digital technologies (e.g., Internet, social media, and digital documentary).


  • Internet access for teacher
  • Classroom map of Great Britain and France
  • Pencil and paper or access to word processing program for students
  • Copies of web based articles or computer access for students
  • Final Project Rubric
  • Coordinate with a librarian to obtain copies of Rick Atkinson, D-Day: The Invasion of Normandy (at least one teacher copy, more if students work independently).

Lesson Preparation

  • Create a page with web links to articles to share with students digitally or open tabs with articles loaded to view as a class.
    • To shorten the lesson, have students read excerpts from Atkinson book and examine websites at home in advance (a flipped classroom model) and be prepared to discuss and participate in activities during class.
  • Hang up or project map of Great Britain and France. Current maps will work for this assignment.
  • Cue links to video clips and web pages prior to class.
  • Decide if you are using printed materials or having students access information on a device. Make copies of articles for paper use, provide hyperlinks if using technology.


Activity One (30 minutes)

  • Post or project a map of France and Great Britain.
  • Examine the map of Great Britain closely and have students identify most likely crossing points for an Allied invasion. Lead a student discussion about potential landing areas on the continent. Ask students to determine a list of criteria for a successful landing and invasion site.
  • Read Atkinson, D-Day: The Invasion of Normandy, pages 19-24, 30-38 and page 180 (this could be pre-assigned as homework if desired).
    • Discuss with students the projected casualty rates for the invasion.
    • Discuss how the Allies kept the sheer number of men and material a secret from Germany.

Activity Two (30 minutes)

  • Watch the video clip D-Day and Operation Fortitude.
  • Read the article from Imperial War Museum, “D-Day’s Parachuting Dummies and Inflatable Tanks.”
  • Explore the ABMC World War II Interactive Timeline for the Normandy Campaign. This activity will allow students to get an overview of Normandy and understand the importance of the success of Operation Fortitude.
  • Lead a discussion over the secrecy involved in planning and executing an operation like Operation Fortitude. Divide students into groups or have them work individually to generate a list of potential problems. Prompt students with the following questions:
    • What issues might the military and government face in keeping the secrecy of this mission? (Teacher tip: Guide students to think and write about the large numbers of men and volume of material needed for Operation Overlord and where the best placement for those men and material should be for a landing at Normandy versus a landing at Pas-de-Calais.)
    • What would be needed to convince the Germans of an entire fake army preparing for invasion?
    • Could an operation like this be successful today? Why or why not?
  • Lead a discussion on the merits of invasion at Calais and the believability of Operation Fortitude. Conduct a whole class discussion or divide students into small groups to discuss:
    • Is Pas-de-Calais a believable site for invasion? Why or why not?
    • Should Allied commanders choose an invasion site based on estimated loss of life?
    • How do you plan for an operation like Fortitude?
    • What are the important components for successful deception?

Activity Three (30 minutes)

Assessment Materials

  • This assessment piece can be completed in class or as a homework assignment. Students should choose one of the following prompts to answer:
    • Imagine you are a soldier participating in Operation Fortitude. Write at least ten journal entries as a soldier participating in this Operation. What are the tasks you are doing? What can you not do? Include details necessary to carry out this deception and remember to use historical details you have read about Operation Fortitude and the correct locations of the troops.
    • Create a Twitter feed of at least 20 tweets from the perspective of a soldier participating in Operation Fortitude. Include clever hashtags and remember you are limited to 140 characters. Your entries must describe where you are, what you are doing, the secrecy involved and accurate descriptions of your surroundings and historical details.
    • Write and perform a short skit with two other students pretending to be soldiers in your unit participating in Operation Fortitude. Include historical details (where are you? What are you doing there? Why are you there?). Costumes are required. Elaborate costumes are not necessary but attention to accurate historical detail (unit badges, etc.) are required for a superior grade.
  • The assessment can be scored using the Final Project Rubric.

Methods for Extension

  • Students can investigate Bletchley Park for a more in-depth look at code breaking.
  • Students can learn about the deceptive radar practices and frequency jamming tools used by the Allies, including Operation Window.
  • Students can hypothesize the increased loss of life and potential alternate outcome if Fortitude was unsuccessful.
  • Students can research the double agents used in this operation.
  • The American Battle Monuments Commission maintains U.S. military cemeteries overseas. These cemeteries are permanent memorials to the fallen, but it is important that students know the stories of those who rest here. To learn more about the stories of some of the men and women who made the ultimate sacrifice, visit the Understanding Sacrifice Interactive Map.


  • Teachers can use the audiobook of D-Day: The Invasion of Normandy, 1944 for struggling readers, English language learners, or auditory learners.
  • Teachers can use the World War II Interactive Timeline from ABMC that include subtitles and audio for accessibility.


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