'Fork' was the British naval delivery and landing of Colonel R. G. Sturges’s 'Sturges' Force (746 men centred on the 2/Royal Marines, with additional weapons) to Iceland in the heavy cruiser Berwick and light cruiser Glasgow, escorted by the destroyers Fearless and Fortune, from Greenock in western Scotland, in the first stage of 'Alabaster' (7/17 May 1940).

At 01.47 on 10 May Berwick catapult-launched a Supermarine Walrus single-engined reconnaissance flying boat to scout the waters off Reykjavík for U-boats, which the Naval Intelligence Division was sure were operating out of Icelandic harbours. The Walrus’s crew was ordered not to fly over Reykjavik but, either by mischance or as the result of a miscommunication, in fact flew several circles over the city, making considerable noise. At this time Iceland possessed no aircraft, so the unusual event woke and alerted a number of people. The Icelandic prime minister, Hermann Jónasson, and the Icelandic police were alerted, and the acting chief of police, Einar Arnalds, suggested that the flying boat was most probably from a British warship bringing the expected new ambassador. This was correct, though it was not the whole story. Werner Gerlach, the German consul, was also alerted and, suspecting that a landing was imminent, drove to the harbour with a German associate and, with the aid of binoculars, confirmed his fears and then hurried back to arrange for the burning of his secret papers. Gerlach also tried unsuccessfully to reach the Icelandic foreign minister by telephone.

At 03.40 an Icelandic policeman saw a small force of warships approaching the harbour, but could not ascertain their nationality. The policeman notified his superior, who in turn notified Arnalds. The laws of neutrality to which Iceland had committed itself forbade more than three warships from a belligerent nation from making use of a neutral harbour at the same time, and aircraft from any such ships were forbidden from flying over neutral territorial waters. Seeing that the approaching fleet was about to violate Icelandic neutrality in two ways, Arnalds set out to investigate. At the harbour, he viewed the ships for himself and decided they were probably British. He contacted the foreign ministry, which confirmed that he should go out to the warships and inform the commander that he was in violation of Icelandic neutrality.

Meanwhile, Royal Marines on Berwick were being ordered to trans-ship to Fearless, which was to deliver them to the harbour. Just before 05.00 Fearless, carrying some 400 Royal Marines, set out for the harbour. A small crowd had meanwhile assembled, this including several policemen still waiting for the arrival of the customs boat which had been ordered. The British consul had received advance notice of the landing and was waiting with his associates to assist the troops when they arrived.

Immediately after docking, Fearless started to land the Royal Marines. Arnalds asked to speak to the destroyer’s captain, but was refused and hastened to report to the prime minister. Jónasson gave him orders not to interfere with the British troops and to try to prevent conflicts between them and any Icelanders.

The British forces began their activities in Reykjavik by posting a guard at the post office, to whose door there fixed a poster explaining in poor Icelandic that British forces were occupying the city and asked for co-operation in dealing with local Germans.

The offices of the Síminn (telecommunication service), the RÚV (broadcasting service) and the meteorological office were quickly put under British control to prevent news of the invasion from reaching Berlin. Meanwhile, high priority was given to the rapid seizure of the German consulate. Arriving her, the British troops encountered no resistance and simply knocked on the door. Opening the door, Gerlach protested against the invasion and reminded the British that Iceland was neutral, himself to be reminded that Denmark had also been a neutral country. In the consulate, the British discovered a fire upstairs and a pile of documents burning in the consul’s bath. They extinguished the fire and salvaged a substantial number of records.

The British had also expected resistance from the crew of Bahia Blanca, a German freighter which had hit an iceberg in the Denmark Strait and whose 62-man crew had been rescued by an Icelandic trawler. The Naval Intelligence Division believed the Germans were reserve crews for the U-boats it believed to be operating out of Iceland. In reality, the unarmed Germans were captured without incident.

After landing the marines, the British warships departed Reykjavik. The two cruisers searched the eastern fjords for German activity and also took on board all German nationals in Iceland for transport to the UK.