On 21 January 1910, Hans Dehn, a master electrician, registers a business for the "installation of electrical systems" with the magistrate of the city of Nuremberg. In addition to local grid and overhead line construction and building installation, the company's business activities also include the installation of lightning protection systems.

Hans Dehn is constantly working on the design of lightning protection components. 
By 1918, he had already been granted his first patent in this field.  
 

Seeing a business opportunity in the still underdeveloped electricity supply sector in the western Upper Palatinate, a branch office is opened in Neumarkt approx. 45 km south-east of Nuremberg, successfully expanding the business base. 

With a pioneering spirit and good ideas, the Nuremberg site now also begins industrial production of its own component programme for lightning protection and earthing.

The company is growing. Hans Dehn also transfers part of the responsibility to his sons Walter and Willy and the family business then starts trading under the name DEHN & SÖHNE. 
In 1941, the youngest son Richard also becomes a co-owner. 
 

The Second World War inevitably impairs business development.

The company buildings in Nuremberg and Neumarkt are badly damaged by the end of the war.

The Dehn family begins to rebuild the company with great vigour.

The nucleus of post-war activities in Neumarkt is an undestroyed warehouse built by Hans Dehn in the final months of the war in the vicinity of our current main site.

Inevitably, during the years of reconstruction, manual work in the field of electrical installation is in demand and ensures the company's survival in the post-war period.

Demand for lightning protection and earthing components slowly begins to pick up again.
The decision to build a hot-dip galvanising plant sets the course for the expansion of the Neumarkt branch as a future production site and production begins again in 1949. 
 

For the first time, DEHN presents lightning protection and earthing equipment at the Hannover Messe.

Hans Dehn, the founder of the company, dies at the end of the year. His sons continue his legacy.

DEHN + SÖHNE exhibits its product range for lightning protection and earthing at the Hannover Messe for the first time. The positive business development soon requires the expansion of the production facilities in Neumarkt.

In addition to lightning protection and earthing, the first development activities are started on the subject of "earthing and short-circuiting". This later evolves into today's safety equipment product range.

A stationary earthing connection, based on the legendary ball pin, is patented in 1953 (inventor Richard Dehn) and over the years becomes a key success factor.  The patented ball pin decisively influences the state of the art.

Austria, a country with a high awareness of lightning protection, becomes the first country DEHN exports to.

Entry into the topic of surge protection, the most important product line today:

DEHN is the very first manufacturer worldwide to launch a low-voltage surge arrester, the legendary J250, on the market.

The sectional earth rod, a pioneering invention, complements the range of components for earthing and is in great demand on the market.

DEHN & SÖHNE becomes a household name in earthing technology.

The 50th anniversary of the family business is celebrated. To mark the occasion, a new administration building is being constructed at the company's headquarters in Nuremberg.

The company is growing and is continually investing in production and new buildings.

DEHN & SÖHNE oHG becomes DEHN + SÖHNE GmbH + Co KG, and the three Dehn brothers involve their children in the family business. 

Walter, Willy and Richard Dehn retire and hand over the management to the third generation.

The first lightning-current-carrying arrester, the DEHNventil, is launched on the market and becomes synonymous worldwide with a new generation of arresters. The company thus expands its leading position in the surge protection market.

The success story of surge protection really began with the VM 280, the world's first modular 17.5-mm arrester for DIN rail mounting.

Internationalisation is intensified and a separate company is founded in Denmark, DESITEK A/S, the first of 22 sales companies worldwide today. 

With the development and realisation of the DEHN 2000 master plan, the company prepares for the future. Successes at home and abroad necessitate comprehensive structural and organisational reform and realignment at the Neumarkt site.

The new energy-coordinated arresters of the Red/Line family for low-voltage consumer installations are presented to the market. Surge protective devices such as DEHNport® and DEHNguard® get successfully underway.

The new energy-coordinated Yellow/Line SPD family for the protection of data technology and automation systems, including the key product BLITZDUCTOR® CT, is another milestone of our research and development.

The technical activities in the field of electrical installation are outsourced to the subsidiary DEHN INSTATEC GmbH, with locations in Nuremberg, Neumarkt and Hermsdorf.

The master plan continues: after moving into new production facilities for surge protective devices in 2002, the new administration building in Neumarkt is completed.

To maintain the important separation distance in lightning protection, a new ground-breaking innovation is developed – the high-voltage-resistant, insulated HVI down conductor – which is well received on the market and is a great boost to the business in lightning protection. 

The managing directors Hans-Joachim Dehn and Dr Peter Hasse retire. Dr Peter Zahlmann is appointed Technical Managing Director.

The new, functional design for the Red/Line® and Yellow/Line product families is presented.

DEHNsupport Toolbox, software for planning and calculating lightning protection systems, comes on the market.

The new three-storey production facility is completed. It represents a further component of the master plan offering 'room to breathe' and a larger production area.

DEHNguard® Y PV SCI is the first arrester to combine surge protection for photovoltaic systems with issues of personal and fire protection.

DEHN celebrates its 100th anniversary: what began as a small electrical installation company is now a global family business.

On the occasion of our anniversary, we support basic research in the field of lightning and surge protection with an endowed professorship at the Ilmenau University of Technology.

On the occasion of the 100th anniversary, DEHN funds an endowed professorship at the Ilmenau University of Technology to promote fundamental research in the field of lightning and surge protection.

One year after the anniversary, Dr Philipp Dehn, son of Thomas Dehn, and a member of the fourth generation of shareholders, joins the company as Managing Director.

DEHNcare®, the new arc-fault-tested protective suit complete with safety helmet and protective gloves for personal protection when working on electrial installations.

With the establishment of additional new sales subsidiaries, the company's international expansion is moving forward; today, there are already more than 20 subsidiaries.

DEHN invests in the future: two mammoth projects are launched.

The new logistics and production site "S2" Mühlhausen goes into operation and SAP software is introduced throughout the company.

In DEHN's expanded test centre, lightning impulse currents of up to 400 kA (10/350 μs) can be generated – a genuine highlight in testing technology.

Im erweiterten Prüf- und Testzentrum von DEHN können Blitzstoßströme bis zu 400 kA (10/350 μs) erzeugt werden, ein absolutes Highlight der Prüftechnik.

The maintenance-free DEHNshield ZP combined surge arrester is launched on the market.

It meets the requirements of DIN VDE 0100-534, which is in force since 1 October 2016, making surge protection in private buildings mandatory.

DEHNguard® ACI is launched on the market. ACI technology – Advanced Circuit Interruption – uses a combination of switch and spark gap eliminating the need for a backup fuse.

After a new general partner joins DEHN + SÖHNE GmbH + Co KG, the company changes its name to DEHN SE + Co KG. The suffix "+ SÖHNE" is sacrificed for internationalisation in order to emphasise the "DEHN" brand alone.

110 years ago, the foundation stone was laid for the family business DEHN as it stands today. For generations DEHN has been protecting people, buildings and facilities.

The coronavirus pandemic spreads worldwide from the first few months of the year. Despite many restrictions, the "Covid years" are quite successful for the DEHNgroup. The ground-breaking ceremony for the construction of the new production facility in Mühlhausen took place in February 2021.

A subsidiary of the holding company founded in 2021, the new DEHN SE, takes over the entire operational business including the companies abroad and the trade-orientated DEHN INSTATEC GmbH.

The "DEHN lightning" word/logo mark from 1949 is now being used again for the external presentation of the company with slight modifications.

The major investment in the new S2.2 production building in Mühlhausen, which began in 2021, is completed and is ceremoniously put into operation. The production facilities for the final assembly of almost all components and devices in the three product groups of lightning protection/earthing, surge protection and safety equipment are now located in new state-of-the-art premises. 650 employees now work at the second site in Mühlhausen.

With a clear focus on ESG principles (Environmental - Social - Government), DEHN is driving forward its transformation and aims to set new standards in the protection of people, the environment and companies.

It´s time to celebrate.