20th Infantry Battalion (NSW) 5th Brigade, 2nd Division, AIF

About This Unit

The 20th Battalion was raised at Liverpool SW of Sydney, in early 1915, to form the fourth Battalion of the 5th Brigade in the 2nd Division.  Its coulour patch reflects these affiliations;  the diamond shape indicates the 2nd Division.  The lower half coloured green indicates the first brigade of the division, and the white upper half is indicative of the fourth battalion in the brigade.

Its soldiers were drawn from NSW, like the rest of the 5th Brigade.  Some of the 20th's original recruits had already served with the Australian Naval and Military Expeditionary Force (AN&MEF) in the operations to capture German New Guinea in 1914. 

The 20th left Australia in late June 1915, trained in Egypt from late July until mid-August, and on 22 August landed at ANZAC Cove.  Arriving at Gallipoli just as the August offensive petered out, the 20th's role there was purely defensive. From 26 August, until its withdrawal from the peninsula on 20 December, the 20th Battalion was responsible for the defence of Russell's Top.

After further reinforcing and re-training in Egypt, the 20th Battalion proceeded to France, landing at Marseilles and then being transported north by rail to French Flanders near the Belgian border.  It entered the trenches of the Western Front for the first time in April 1916 in ‘ The Nursery‘ Sector near Armentieres; later to be come infamous because of the village to their front - Fromelles.

In the following month had the dubious distinction of being the first Australian battalion to suffer a trench raid by the Germans. 

The 2nd Division moved south to the Somme along with the 1st and 4th Divisions to join the great Somme Offensive which had started disastrously for the British who were supposed to be relieving pressure on  the French at Verdun.  

The 20th took part in the attack on Pozieres and later Bouquet Farm between late July and the end of August 1916.

After a spell in Belgium, the 2nd Division, which included the 5th Brigade, came south again in October. The 2nd Division was slated for action near Flers and the 20th Battalion provided reinforcements for the attack near Flers between 14 and 16 November, launched in conditions that Charles Bean described as the worst ever encountered by the AIF.  It was the worst winter in living memory.

In early 1917, the 20th was involved in the follow-up of German forces after their retreat to consolidtae their front on the Hindenburg Line.  The four battalions of the 5th Brigade withstood and defeated a German counter-stroke force, more than a Division strong, at Lagnicourt.

The 20th Battalion took part in three major battles before the year was out, second Bullecourt (3-4 May) in France, and then as part of the Third Ypres campaign in Belgium at Menin Road (20-22 September) and Poelcappelle (9-10 October).

On 21 March 1918, a massive German Offensive erupted across the Allied Front, aimed particularly at the British 5th Army on the Somme.  ‘Operation Michael’ and its subsidiary offensives, aimed to dislocate the Allies and seize the Channel Ports which would have caused the French to sue for peace on German terms had it succeeded, before US Forces could arrive in decisive numbers,

The AIF was used as a metaphorical "Fire Brigade" with Brigades being penny packeted all over the Front; a move which spurred Government insistence on the formation of an Australian Corps under Australian Command, mirroring the Canadians.

The 20th Battalion, the 5th Brigade and indeed the rest of the AIF, were rushed to stop gaps in the crumbling British line.  The 20th Battalion found itself on the outskirts of Villers Bretonneux and engaged in desperate fighting when ordered to attack at Hangard Wood on 7 April.

The Division and its Battalions were active in the period known as ‘Peaceful Penetration’, advancing the line by limited but coordinated attacks on German defensive outposts.

Le Hamel was the first test of the new Corps structure, but most importantly the tactis that Monash had been advocating;  each Division had at least a token representation in the Order of Battle.  It was a set-piece demonstration of the application of Combined Arms theory and it worked perfectly.  The 2nd Division contribution comprised elements of the 6th and 7th Brigades, including the 21st 23rd and 25th Battalions on the southern flank of the attack.  It was all over in 93 minutes, and Monash’s position as Corps Commander was secure.

A month later and it was time for the main event as the Battalion took its place in the Australian for the Great Allied offensive, the "Last Hundred Days" campaign beginning on the 8th August 1918 with the Battle of Amiens.  British III Corps north of the Somme, then the Australian and Canadian Corps side by side south of the Somme coordinated with the French Army further south.

The 2nd Division started the Amiens offensive on the right hand flank, leading ‘two-up’ with the 3rd Division on the left.    The 4th and 5th Divisions followed respectively with the 1st Division as Reserve.  Surprise, synchronised artillery that had achieved registration of targets using data from new sound-ranging techniques, and the shock action imparted by use of tanks on a scale hitherto not seen led to spectacular gains as Monash had forecast at Le Hamel and initial objectives were achieved within three hours.

The 2nd Division’s ‘finest hour’ was the attack on Mont St Quentin from 30 August to 2nd September in concert with the 5th Division which cleared the town of Peronne after a risky river crossing of the Somme.  The 6th Brigade’s consolidation of the heights of the Mont was the turning point of the battle.

The 20th Battalion was in the thick of the fighting throughout. Montbrehain was the 20th Battalion's (and the AIF’s) last battle of the war. After the 2nd Division attack on the Beaurevoir Line at Montbrehain on the 5th October, the AIF was withdrawn from the line to reinforce and refit following the accumulated losses it had sustained since 8th August.  It was out of the line on 11th November when the Armistice was declared and disbanded on 20 April 1919.

Commanding Officers

Lamrock, John
Ralston, Alexander Windeyer
Bennett, Alfred Joshua
Forbes, Frederick William Dempster


Battalion personnel were awarded the folloing decorations & awards during the course of their service in the Battalion; 
1 VC; 1 CB; 2 CMG; 9 DSO; 1 MBE; 24 MC, 4 bars; 19 DCM, 2 bars; 103 MM, 6 bars; 6 MSM; 38 MID; 13 foreign awards

Battle/Campaign/ Involvement

Gallipoli, 1915 (/explore/campaigns/1)  25 Apr - 19 Dec 1915

Pozières (/explore/campaigns/6) (includes Mouquet Farm) 23 Jul - 12 Sep 1916

Flers / Guedecourt (/explore/campaigns/24)   18 October - 16 November 1916

Bapaume, 1917 (/explore/campaigns/21) (Outpost Villages etc) 15 Feb - 3 Apr 1917

Bullecourt (/explore/campaigns/6)  3-11 May (2nd) 1917

Menin Road (/explore/campaigns/26)   20-21 Sep 1917

Polygon Wood (/explore/campaigns/19)  24-25 Sep 1917

Broodseinde (/explore/campaigns/18) 4 Oct 1917

Poelcappelle (/explore/campaigns/27) 9 Oct 1917

Passchendaele (/explore/campaigns/28)  24 Oct - 10 Nov 1918

Albert, 1918 (German Spring Offensive 1918 (/explore/campaigns/80)) 21 March - 1 May 1918

Hamel (/explore/campaigns/33)  4 Jul 1918

Amiens (/explore/campaigns/14) 8 Aug 1918

Mont St. Quentin (/explore/campaigns/15) 31 Aug - 2 Sep 1918

Hindenburg Line (/explore/campaigns/81) 28 Sep - 5 Oct 1918

Beaurevoir (Montbrehain) (/explore/campaigns/128) 5 Oct 1918

Generic Battle Honours

Egypt, 1915-16

Somme, 1916, '18

France and Flanders, 1916-18

Ypres, (/explore/campaigns/23) 1917

Originally compiled 2014 and updated by Steve Larkins Dec 2020


AWM 224: V.B. Portman, '20th Australian Infantry Battalion: Narrative by Capt V B Portman. Gallipoli, Passchendaele, Somme, 1918'.



We would particularly like to encourage individual historians researchers or members of unit associations to contribute to the development of a more detailed history and photographs pertaining to this unit and its members.

Please contact  [email protected] (mailto:[email protected]) for details on how to contribute.



The 'A' ANZAC motif

'ANZAC' insignia

Members of the Australian Imperial Force who served on Gallipoli will be entitled to wear over the Unit “Colour Patch” on both sleeves of the Service Dress Jacket and Greatcoat the letter “A” an indication that the wearer had taken part in the operations on the Gallipoli Peninsula. - Military Order 354 of 1917

Members of the Australian Imperial Force who served on Gallipoli or the Islands of Lemnos, Imbros and Tenedos, or who have served on transports or hospital ships at or off Gallipoli or the Islands above-named, or in AIF lines of communication Units in Egypt will be entitled to wear over their Unit “Colour Patches” on both sleeves of their Service Dress Jacket and Greatcoat the letter “A” as an indication that the wearer had taken part in the Gallipoli operations. - Military Order 20 of 1918


Interpreting AIF Colour Patches

The colour patches which identified units in the AIF were designed to show what division or service they belonged to, and also, in the case of infantry units, their brigade and the sequence of the Battalion in that Brigade.

The shape of a colour patch indicated the division or service -
1st Division - horizontal rectangle split horizontally
2nd Division - diamond shape split horizontally
3rd Division - horizontal ellipse
4th Division - circle split horizontally
5th Division - vertical rectangle split vertically.

The lower colour denoted the brigade's sequence in the Division. Usually (but not always!) these colours were:
Green - first brigade in the division
Red - second
Light Blue - third

The 4th Brigade, originally in the 1st Division , had a dark Blue lower half. Its reallocation to the 4th Division after Gallipoli threw both the brigade / battalion numbering sequence (the most logical at any time in the history of the ADF) and the colour patch structure into disarray!

In the first AIF there were four infantry battalions to each brigade, and the upper section (or LHS in the case of the 5th Division) of the colour patch identified each one. Usually (but not always!) these colours were:
Black - first
Purple - second
Brown - third
White - fourth

Thus every battalion had a unique colour patch.

Other Arms and Service Corps had variations but those attached to the five divisions generally incorporated the shape of their parent Ddvision.

Source: Text taken from The 27th Battalion Centenary: The Historical Record of the 27th Battalions 13th August 1877-1977 and Programme of Centenary Celebrations, Unley SA, 1977

1. Strictly speaking there was no such thing as the 'First AIF'. The term is often used unofficially to distinguish the Australian Imperial Force of the First World War from the Second AIF raised to fight in World War 2.

2. The colour patch scheme was first introduced into the AIF in March 1915, just in time for the initial Gallipoli landings. The 2nd Division received its patches in August 1915, and gradually the scheme was expanded to include the whole AIF.

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