Click for homepage
Timeline →
Patents →
Enigma family tree
Version 0.50 - 27 January 2019 - under construction

This page shows all currently known Enigma models and how they are related to each other, in the form of a family tree. The family tree is the result of a cooperation between Paul Reuvers and Frode Weierud and is subject to copyright. If you want to use it for your own publication, please read the conditions and the disclaimer at the bottom of this page.

Important notice — An earlier version of this page was based on the classical understanding of the Enigma model names, such as Enigma A, Enigma B, Enigma C, etc. However, documents discovered in 2018 show that some of these model names are incorrect. This affects in particular our view on the printing Enigma machines (Schreibende Enigma) and the early glowlamp-based machines. The information below is based on the new insights, but is currently under development and may be changed without notice.
Family branches
Between 1918 and 1923, inventor Arthur Scherbius developed a number of prototypes — Die Probemaschinen — which evolved into a family of Enigma cipher machines, the first of which was released in 1923. Between 1923 and 1945, this family had two branches: (1) a line of machines that printed directly to paper, and (2) a line of simpler – much cheaper – machines that used glow lamps (light bulbs) for their output. The latter is the most well-known and successful branch.

Printing Enigma machines
The first Enigma machine to be released — some time in 1923 — was Die Handelsmaschine (the commercial machine, or trade machine). It was first discussed by the inventor – Arthur Scherbius – in a technical magazine in November 1923. It prints directly to paper using a print wheel, and has four cipher wheels, with 28 contacts each. This machine has several spin-offs.  More

In the following year – 1924 – a different approach was tried, with type bars instead of a print wheel, but it was not until 1926 that the mechanical and production problems had been solved and the machine was mature enough to be sold. It became known as Die schreibende Enigma (the printing Enigma), but is also known as Die Typenhebelmaschine (the type bar machine).  More

The last printing Enigma machine was introduced in 1929. It was given the model name Enigma H29 (internal designator Ch.14) and used push-bars instead of the error-prone type-bars of the earlier machine. It was sold to the Hungarian Army, and to the German Reichswehr (Wehrmacht) were it was known as the Enigma II. It was also used as a printer for other models.  More

Glow lamp Enigma machines
Shortly after the introduction of the first Enigma machine – in 1923 – development of a simpler, more portable, and more affordable machine was started. Rather than printing its output directly to paper, this machine produced its output on a panel with light bulbs; one for each letter of the alphabet. This branch was known as the Glühlampenmaschine (glow lamp machine) and would eventually evolve into a complex line of machines of which many thousands were manufactured.

The branch of glow lamp machines started in 1924 with the introduction of the Enigma A, which was also known as Die kleine Militärmaschine (the small military machine). It was soon followed by the Enigma B, which eventually evolved into the Enigma C. Several variants of the Enigma A, B and C were developed, before the design evolved into the Enigma D (internal designator Ch.8), or Enigma Model A26, that can be seen as the basic design on which all later machines were based.

Exclusively for use by the German war machine, a Steckerbrett (plug board) was added to the design of the Enigma D in 1927 (internal designator Ch.11a). This would be the starting point of the military machine that was known by the Wehrmacht as the Enigma I. This branch is shown in green in the above diagram, and includes the naval machines M1, M2, M3 and M4 (Ch.11g & g4). This is arguably the most famous Enigma branch, of which tens of thousands were manufactured.

A special branch, which also descends from the Enigma D, is the line of cogwheel-driven Enigma machines, known as Die Zählwerksmaschinen (the counter machines, or cogwheel machines). Starting with an early variant in 1927 and the improved Enigma Model A28 (Ch.15) in 1928, this line eventually evolved into the somewhat smaller Enigma Model G31, or Enigma G (Ch.15a). Several varants of the latter were developed (Ch.15b & Ch.15c), of which only one has survived.

A little-known branch is the line of numbers-only machines, known as Enigma Model Z30, or Enigma Z, here shown in yellow. There are two known versions, one of which descends from the Enigma D, whilst the other one also contains influences of the Zählwerk Enigma A28. It is likely that only a small number was manufactured. Examples of the first variant (Ch.16) have survived.

In parallel with the other branches, a line of commercial machines was developed between 1927 and 1944, all of which were based on the Enigma D. This line is generally known as the Enigma Model A27 or Enigma K, although the letter K was not used as a serial number prefix until 1936.

How to use the tree
The table consists of a number of circular 'balloons' each of which describes a single model or variant. We've tried to provide as much information as possible both inside and outside the balloons. Arrows are used to point to descendants and variants of a particular machine or model.

Inside each balloon are three pieces of information. The topmost one is the official model number (when known) that was used in brochures and offerings (e.g. Z30). At the centre is the popular name by which the machine is commonly known, for example: Z or M4. At the bottom is the internal designator used by the manufacturer in internal documents and drawings, e.g. Ch.15a.

At the top left is the year of development or introduction, shown in red. When known, the green number to the right of the year, shows how many machines of this model were made on average. At the bottom right are two numbers printed in blue. The upper one shows the number of contacts on each wheel. The lower one shows the number of turnover notches on each wheel.

Preliminary information
The Enigma family tree is largely based on many years of historical research of the Enigma machine, that is currently being carried out by Frode Weierud in Norway. The full results of his research are expected in the form of a future publication in Cryptologia. Until that time, the tree may change regularly as new information is discovered. The bottom right of the tree shows the current version number and release date. This information is also printed at the top of this page.

Conditions for using the Enigma Family Tree
Please note that the copyright of the Enigma Family Tree belongs to Paul Reuvers and Frode Weierud. If you want to use it in your own publication, you may do so without prior permission, if you meet all of the following conditions:

  • It is not used for commercial purposes.
  • You do not modify or alter the tree.
  • You do not remove or alter the copyright notice.
  • You show the version number and release date.
  • You give full credits to the authors plus a link to this page.
  • You state that this is preliminary information.
If any of the above conditions can not be met, you should contact us first in order to ask for permission. When requesting permission, please provide as much information about yourself and your intended publication as possible.

DISCLAIMER — All information on this page is believed to be correct at the time of writing but there is no guarantee that this is the case, nor that the information is suitable for any purpose whatsoever. Please note that this page is subject to continuous changes without notice. Under no circumstances can we be held responsible for the information presented here. If you have additional information, or if you believe that some of the information is incorrect, please do not hesitate to contact us.
  1. Enigma Family Tree
    The current version of the family tree is currently not available for download, as it is undergoing a major revision. Until that time, you may want to use the previous version.
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Thursday 10 September 2009. Last changed: Thursday, 20 April 2023 - 08:12 CET.
Click for homepage