The Senussi were a religious sect mainly of Libyan nomads, who had fought the Italians in Libya during the Italo-Turkish War (29 September 1911 – 18 October 1912).

Britain declared war on the Ottoman Empire on 5 November 1914 and in the summer of 1915, Turkish envoys, including Nuri Bey, brother of Enver Pasha and Jaafar Pasha, negotiated an agreement with the Grand Senussi, Sayyid Ahmed ash-Sharif, to attack the British in Egypt from the west, during the Ottoman offensive through Palestine against the Suez Canal, known as the Raid on the Suez Canal.

[1] The Senussi raised 5,000 infantry and other irregular troops, equipped with Ottoman artillery and machine-guns, for campaigns along the coast against Sollum, Mersa Matruh and Da'aba on the way to Alexandria and from Siwa through the band of oases, Bahariya, Farafra, Dakhla and Kharga, 100 mi (160 km) west of the Nile.

[3] Wallace suffered from an old wound and was relieved by Major-General William Peyton and the WFF was reinforced with the 1st South African Brigade (Brigadier-General Henry Lukin) and a detachment of Egyptian engineers on 4 February.

The WFF eventually received 2,000 camels, which made the force capable of advancing a greater distance and the ability to maintain itself in the desert.

[4] On 6 November 1915, U-35 sank HMS Tara and the coastguard gun-boat Abbas, and badly damaged Nur el Bahr in the Bay of Sollum.

The British withdrew from Sollum to Mersa Matruh, 120 mi (190 km) east, which had better facilities for a base and the Western Frontier Force (Major-General Alexander Wallace) was created.

On 20 February, Lukin advanced towards Unjeila with orders to reach Sidi Barrani quickly, with the 1st and 3rd South African Infantry battalions, the Dorset Yeomanry, Bucks Hussars, 6th Royal Scots, most of the Notts Battery of the 1/1st Nottinghamshire RHA and a field ambulance.

[9] During the march, air reconnaissance discovered a Senussi encampment at Agagia, 15 mi (24 km) south-east of Sidi Barrani.

The guns were silenced by the British artillery and the Senussi were driven off; expecting more attacks, Lukin abandoned the night march.

Next day, the yeomanry reconnoitred at 5:00 a.m. and discovered that the Senussi were still at Agagia with no outposts, occupying sand hills with about 1,500 men, three guns and five machine-guns.

Losses mounted as the advance closed up to the sand hills and Jaafar sent a counter-attack against the South African left flank.

[13] After resting, the yeomanry attacked in two lines at a steady gallop, receiving return fire from the Senussi, which was accurate at first, became wilder and then ceased.