During the attack on Tulkarm, the infantry created a gap in the Ottoman front line defences, through which cavalry from General Edmund Allenby's Egyptian Expeditionary Force (EEF) rode north.

The three cavalry divisions in the Desert Mounted Corps successfully captured the Ottoman Seventh and Eighth Armies' lines of communication across the Esdraelon Plain from their headquarters in the Judean Hills.

As the 4th Cavalry Division rode out across the Esdraelon Plain on the morning of 20 September, towards their primary objective; the main communications hub at Afula, they attacked and captured a force sent from Yildirim Army Group headquarters at Nazareth, to hold and bar the Musmus Pass, which had failed to get into position.

Several days later while garrisoning Beisan, the 4th Cavalry Division advanced southwards down the Jordan River to close a 20 miles (32 km) long gap, through which the retreating remnants of the Seventh and Eighth Armies had been escaping.

By the end of the month, one Ottoman army had been destroyed, while the remnants of two others were in retreat to Damascus after the German rearguard at Samakh was captured by Australian Light Horsemen on 25 September.

[2] Aerial reconnaissance reported that no defensive works of any kind had been identified on the plain or covering the approaches to it, apart from German troops, garrisoned at the Yildirim Army Group headquarters of Otto Liman von Sanders at Nazareth.

[3][Note 1] At 12:30 on 19 September Liman von Sanders ordered the 13th Depot Regiment at Nazareth and the military police, a total of six companies and 12 machine guns, to occupy Lejjun and defend the Musmus Pass.

The 5th Cavalry Division was to travel by the northern and more difficult track, from Sindiane to Abu Shusheh 18 miles (29 km) south-east of Haifa and on to attack Nazareth.

[5][10][21] If they could quickly capture the Esdraelon Plain while the two Ottoman armies were fighting in the Judean Hills against the XXI Corps infantry in the Battle of Sharon, and the XX Corps infantry in the Battle of Nablus, the railways could be cut, the roads controlled, and the lines of retreat across the plain for these two Ottoman armies west of the Jordan would be virtually cut.

[17] The 5th Cavalry Division's objectives were to capture Nazareth, Liman von Sanders, and the Yildirim Army Group's headquarters 70 miles (110 km) from Asurf, before clearing the plain to Afula.

The Australian Mounted Division, in reserve, was to enter the Esdraelon Plain and occupy Lejjun while the 3rd Light Horse Brigade advanced to capture Jenin, 68 miles (109 km) from their starting point.

"[22][Note 4] Victory at Megiddo depended on controlling the skies by destroying or dominating German aircraft activities and reconnaissances, through constant bombing raids by the Royal Air Force (RAF) and Australian Flying Corps (AFC), on Afula to disrupt communications between the Yildirim Army Headquarters at Nazareth and the Seventh and Eighth Armies' headquarters at Tulkarm and Nablus.

[24] The 4th Cavalry Division advance began at 09:00, riding through the Ramadan and Zerkiyeh marches, and northwards towards Liktera and the southern end of the Musmus Pass 25 miles (40 km) away.

[1] The pass rises to 1,200 feet (370 m) above sea level, as it follows the Wadi Ara up the southern side of the Samarian Hills, at the time only about 300 yards (270 m) wide.

[37][Note 7] After arriving at Lejjun at 03:30, the 2nd Lancers watered, fed, and breakfasted before setting out at 05:30 for Afula on a "three-squadrons front followed by the 11th Light Armoured Car Battery and a subsection of the 17th Machine-Gun Squadron."

Ten minutes later, the centre squadron was fired on by six companies of the 13th Depot Regiment and military police, supported by 12 machine guns, which Liman von Sanders had ordered to occupy the Musmus Pass at Lejjun at 12:30 on 19 September.

[40] ... bullets were coming unpleasantly close ... [as I] edged towards the right with the intention of locating the enemy's left flank ... Just then the squadron ran into a wire fence hidden in the jowar [millet] which covered that part of the plain.

We were moving at a good 15 miles (24 km) an hour by now ... but I was still in mortal terror that the Turks' determined stand might be fortified by the knowledge that a deep nullah lay between themselves and us ...

By the evening of 20 September rations had also been delivered to the 5th Cavalry Division at Aujah by motor lorry via the Musmus Pass, while 'A' Echelon and the Divisional Transport Train were bivouacked at Qaqun.

[37] Accompanied by a section of the 18th Machine Gun Company and a party of the 4th Field Squadron Royal Engineers, the regiment left Afula at 19:30 after handing over to the 5th Cavalry Division.

The continuing British Empire infantry attack in the Judean Hills had forced the Ottoman Seventh and Eighth Armies to withdraw northwards towards the waiting Desert Mounted Corps.

[59] By dusk on 19 September, 4,000 prisoners had been captured and brigade transport following the cavalry divisions was 20 miles (32 km) behind enemy lines in what had been Ottoman Empire territory.

[61] Liman von Sanders had no combat formations available to stop the cavalry advance up the coast and across the Esdraelon Plain; Allenby's attack forced the Yildirim Army Group and its commander to retire.

[65][Note 9] The Jisr ed Damieh bridge, which carried the Wadi Fara road from Nablus across the Jordan River, was captured on 22 September by Meldrum's Force, comprising the New Zealand Mounted Rifles Brigade and 1st and 2nd Battalions, British West Indies Regiment, supported by artillery.

[62] Late in the evening of 22 September, Chauvel ordered Barrow's 4th Cavalry Division to advance south from Beisan along the Jordan River to close a 20 miles (32 km) gap north from the Jisr ed Damieh bridge, which Chaytor's Force had captured.

[69] The 11th Cavalry Brigade advance southwards; the 36th Jacob's Horse on the east bank was fired on, 4.5 miles (7.2 km) south of Beisan to the south-east of Khirbet es Samriye.

A long column of retiring Ottoman soldiers was attempting to cross the Jordan River at Makhadet Abu Naji under cover of a 1,000-strong rearguard with 30 machine guns.

The commander of the 16th Division, Rushdi Bey, and 18 machine guns were captured, along with 800 prisoners, which were later identified to have been the rearguard of von Oppen's Asia Corps.

The 1/1st County of London (Middlesex) Yeomanry began their attack from both sides of the river and eventually captured the ford, along with 4,000 prisoners, leaving many dead.

At 15:00 the defenders withdrew from the Makhadat Abu Naji ford, "suffering very heavily indeed from machine-gun and automatic-rifle fire, and abandoning an enormous amount of material.