“As we got near [to Nakhl Mubarak] we saw through the palm-trees flame, and the flame-lit smoke of many fires, while the hollow ground re-echoed with the roaring of thousands of excited camels, and volleying of shots or shoutings in the darkness of lost men, who sought through the crowd to rejoin their friends. As we had heard in Yenbo that the Nakhl were deserted, this tumult meant something strange, perhaps hostile  …

“We ploughed our way through this din, and in an island of calm at the very centre of the valley bed found Sherif Feisal … he explained to me what unexpected things had happened in the last twenty-four hours on the battle front. The Turks had slipped round the head of the Arab barrier forces in Wadi Safra by a side road in the hills, and had cut their retreat. The Harb, in a panic, had melted into the ravines on each side, and
escaped through them in parties of twos and threes, anxious for their threatened families … Then [Zeid] escaped himself; but his force melted into a loose mob of fugitives riding wildly through the night towards Yenbo. Thereby the road to Yenbo was laid open to the Turks, and Feisal had rushed down here only an hour before our arrival, with five thousand men, to protect his base until something properly defensive could be
arranged.”

Events of 2 December 1916 as recounted by T. E. Lawrence in Seven Pillars of Wisdom (1926).

By the time Lawrence arrived back in Yenbo, things in the Hejaz had changed. Feisal had moved his army to Wadi Yenbo in preparation to attack the railway, while Zeid was moving inland from Rabegh to take up a supporting position in Wadi Safra. Ali was stationed in Rabegh, while Abdullah was still blockading Medina.

When Lawrence rode out from Yenbo to meet Feisal,  he was surprised to encounter his army near the date plantations at Nakhl Mubarak. The story told by Feisal of the collapse of Zeid’s men, followed by his own retreat on Nakhl Mubarak, proved to be the start of a week of crisis, as Yenbo suddenly found itself laid vulnerable to the Turks.