Batterie Mirus is probably the most well known of the German gun batteries in the Channel Islands. Probably because it was the largest on any of the Channel Islands.

The name of the gun batterie was in honor of Kapitan-zur-See Rolf Mirus, who was killed in 1941 while sailing between Guernsey and Alderney.

They had a range of 51km (31.5 miles). The image below shows the impact this could have on shipping in the area.

Range of guns shown on website

If you have read some of my tweets and blog posts you will be familiar with the Germans taking captured equipment and reusing it themselves. This is features in a number of aspects of the construction of the battery itself.

The 30.5cm (12 inch) guns themselves had a couple of previous owners including a short period with the Germans. Originally they were the main armament of a Russian battleship captured by the Germans and then returned to the Russians at the end of the First World War. After the battleship was broken up in the mid 1930s the guns were placed in storage before being pressed into use in the Russo-Finnish war. Captured by the Germans they were sent back to Germany to be reconditioned. Then onwards to Guernsey.

As you can imagine they were not easy to transport at any stage of the journey. Arriving at St Peter Port on barges a special crane was required to lift them. 50 ton guns will not be easy to move.

What was required was a crane with a large lifting capacity. The Germans had captured one from the French, the barge ANTEE, with a tested lifting capacity of 100 tons. This was dispatched from France to Guernsey and can be seen in the photographs below.

The next problem was transporting them, for which 48 wheeled trailers were used. If you are familiar with Guernsey roads you will know that they are often quite narrow and not particularly straight. The dotted lines on the Google Map below show where the harbour at St Peter Port is and then the location of the Batterie Mirus which is in the Guernsey countryside at the far end of the Island.

Some junctions such as the one shown below had to be widened to enable the trailers to get through. The pictures below show some of the challenges they faced.

You can see from the photograph below the difficulties in navigating the guns through the narrow lanes once they reached the area near the gun pits.

Once at the sites they then had the problem of lifting the guns into place. This was achieved using the massive cranes that you can see in the pictures below. You can see from looking at the people in the photographs the scale of the guns.

An incredible 45,000 cubic metres of concrete were used in construction of the four gun pits and supporting buildings.

Concrete mixers on construction.

Once completed it was disguised as a house. This was an attempt to hide it from reconnaissance flights. In reality the Allies were well aware of the construction because of photo reconnaissance missions during the course of construction.

© IWM HU 25925
© IWM HU 25926
Mirus Control Room © IWM HU 25928

I found an interesting account “The Grower’s Tale” in the June-July 2014 edition of “Shore to Shore” a magazine for the Parishes of St. Saviours & the Forest.

The first that Renaut de Garis knew that these guns were coming to stay, was when his brand new brick house, La Croix in La Vieille Rue, was requisitioned. He and his pregnant wife were moved down to the Grand Douit behind Perelle. La Croix was given a reinforced first floor: steel beams and a foot of concrete; and the Commander of the gun battery moved in.

Interviewed in 2009 aged 95 (he was 100 this May), Renaut remembered it all: “They were Spaniards building the battery, we called them Morroccans. Some of them were quite refined people. They were treated terribly, poor devils. Soupe d’Atlantique, they called the food they gave them, it was just water really. Disgusting.

In the winter they wrapped cement sacks round their feet to try and keep them warm. If British planes were overhead, the Germans would cut all the lights at their building sites, but not the power to the concrete mixers. Those huge mixers just ran and ran, night and day.

After they had built the battery they covered it all back with earth again. There used to be a little valley there, and now it’s flat. When they were going to test the [Number 2] Mirus gun the first time, most people didn’t want to go. The shock of the detonation was tremendous. I had my young son in my arms at the time… I saw his cheeks rippling with the shock wave. I had three greenhouses and they were just lifted up and moved sideways. The glass was like snow on the ground. 

“The Grower’s Tale” in the June-July 2014 edition of “Shore to Shore” a magazine for the Parishes of St. Saviours & the Forest.

Below is a video from YouTube which shows the transport issues and firing.

The guns were fired numerous times from 13 April 1942 onwards.

When they were test fired large numbers of the population had to move out of the area and much disruption was caused. One can only imagine what happened when they were fired without warning. The picture below is from a document I found in the Island Archives relating to restrictions on test firing.

AQ696/08 Island Archives
From a report to the Historical Division of Group West. It was written in May 1948 by Major General Graf von Schmettow who was commander of the Channel Islands until his removal on 20 February 1945. Usefully there was an English translation.

The Guns were removed after the war as part of the scrap drive. You can see below a photograph of the site maintained by Festung Guernsey. Don’t be fooled by the photograph this is a massive site. The video at the end of the blog will help you appreciate just how big this site is.

Photo Copyright Nick Le Huray

Entrance to the gun pit. Photo Copyright Nick Le Huray
Picture from Weapons & Warfare gives an idea of the scale of just one of the gun sites.

Below is a great video with an overview of the site.

If you want to learn more about the Batterie Mirus and visit the site of one of the guns I highly recommend the tour that is run by Tours of Guernsey around the site maintained by Festung Guernsey. I recently took the excellent tour and posted about it below. If you go on the tour you will find out far more than I can write in a blog post. Plus nothing is as good as walking the ground!

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I will be adding more as time permits. Thank you for taking the time to read this, and I hope you enjoyed it. Please share it on social media or add a comment if you did. Feedback is always appreciated.

Also happy to be contacted with questions about the war in the Channel Islands, media appearances, podcasts etc.

© Nick Le Huray

Author: Nick Le Huray 🇬🇬

Guernsey based amateur historian. Interested in the Occupation of the Channel Islands and wider Second World War history.


  1. “From Hostility to tranquillity” it say at the gun pit. More a world message than just an Island one. See where we’ve been to know where we’re going.

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