'Cutthroat' (i) was an Australian offensive in New Guinea, otherwise known as the 'Battle of Shaggy Ridge', and involving the actions known as the 'Battles of Faria Ridge, Prothero I and II, McCaughey’s Knoll and Kankiryo Saddle' in the 'Campaign for the Finisterre Mountain Range' (19 September 1943/24 April 1944).

This was part of the campaign for the Ramu river valley and Finisterre mountain range in north-eastern part of New Guinea, and began with an Allied offensive in the Ramu river valley from 19 September 1943, and concluded with the entry of Allied troops into Madang on 24 April 1944. During the campaign Australian and US forces assaulted Japanese positions in the Finisterre mountain range of New Guinea, whose central geographical and strategic feature was the imposing Shaggy Ridge, running north/south and the highest feature in the Finisterre mountain range.

The Finisterre range campaign began in September 1943, following the drive of Major General George A. Vasey’s 7^th Division on Lae, as part of the larger and farther-flung New Guinea campaign, which saw Major General George F. Wootten’s 9^th Division carrying out operations along the Huon peninsula on the coast to the east, while the 7^th Division moved toward the west. Carrying out a number of smaller-scale operations, the units of Brigadier I. N. Dougherty’s 21^st Brigade and Brigadier K. W. Eather’s 25^th Brigade advanced up the Markham and Ramu river valleys. Apart from a significant engagement around Kaiapit, where the 2/6^th Commando Squadron captured the village and killed more than 200 Japanese, the Australians were barely resisted as they advanced to reach Dumpu early in October.

After this, the 7^th Division provided security as several airfields were constructed in the territory the division had captured in the valleys. The Japanese remained in strong possession of the Finisterre range, however, and their positions at the Kankiryo Saddle to the north of the Ramu river and the 4,900-ft (1495-m) razorback Shaggy Ridge, continued to threaten the airfields. This threat became clearer as the Japanese attempted to build a road from Madang on the coast inland to Nadzab via Bogadjim: it was clear that the Japanese were planning advance along this to Dumpu.

The Kankiryo Saddle and Shaggy Ridge were therefore of vital strategic importance for both the Japanese and the Australians. For the Japanese, it provided a strong obstacle to the Australian advance to the north in the direction of the coast, while also providing them with the ground along which they could launch their own offensive in order to recapture the territory they had lost earlier in the campaign. For the Australians, the Japanese positions on the high ground indicated a major threat, and they accordingly decided to launch a major offensive of their own in order to take this ground.

The result was a series of comparatively small but distinctly hard-fought battles in the steep and deeply inhospitable mountains of the Finnisterre range. In October, battles took place at Palliser’s Hill and then later at Johns' Knoll where the Australians first managed to capture the knoll and then to hold it against a determined Japanese counterattack. In November, the 25^th Brigade relieved the 21^st Brigade as the Australians maintained their offensive, and later in December and into January there was heavy fighting around Shaggy Ridge and the Kankiryo Saddle. Shortly after Shaggy Ridge had been captured, Brigadier F. O. Chilton’s 18^th Brigade was replaced by Brigadier H. H. Hammer’s 15^th Brigade, a militia unit, and the 7^th Division advanced toward Bogadjim, linking with the US forces there on the coast, before finally securing the Huon peninsula on 24 April 1944 when they took Madang.

The Japanese formation in the Finisterre range campaign was Major General Masutaro Nakai’s 'Nakai' Detachment, which was a brigade-sized formation detached from Lieutenant General Shigemasu Aoki’s 20^th Division of Lieutenant General Hatazo Adachi’s 18^th Army, and this was opposed by Major General Arthur S. Allen’s (from October Vasey’s) Australian 7^th Division.

The razor-backed Shaggy Ridge is 6.5 miles (10.5 km) long, rises between the valleys of the Mene and Faria rivers and ends at the Kankiryo Saddle, which is a bridge of land separating the valleys of the Faria and Mindjim rivers.

In 1943 Shaggy Ridge was the site of main Japanese defensive position blocking access from the Ramu river valley to the track and road network that joined it with the northern coast. Operations by the 7^th Division in September and October 1943 had caused the Japanese to pull back from the Ramu river valley and the lower features of the Finisterre mountains in order to consolidate their defences around Shaggy Ridge, so named for Captain Robert 'Shaggy Bob' Clampett of the 2/27^th Battalion, whose company was the first to reconnoitre its approaches.

Initially, the orders of Lieutenant General Sir Leslie Morshead’s Australian II Corps to the 7^th Division, limiting its operations to a scale that could be maintained by the flow of supplies and ammunition currently available, prevented action being taken to capture Shaggy Ridge, but by a time late in December sufficient supplies were available to conduct a limited operation to secure a foothold on the southern end of the ridge around a knoll called the Pimple. B Company of the 2/16^th Battalion attacked just after 09.00 on 19 January after an intense air and artillery bombardment of the Japanese positions. Clambering up the precipitous slopes, still supported by artillery fire, the Australians quickly captured the Pimple and pushed on for another 110 yards (100 m) to capture the next knoll along the ridge. B Company was subsequently relieved by D Company, which renewed the attack on the next day and captured the next two knolls along the ridge, the last being named McCaughey’s Knoll after the commander of the leading platoon.

The Japanese counterattack of the afternoon of the same day was beaten off, and after this the Japanese limited themselves to shelling if the Australians' newly won position with a mountain gun. The next major assault along Shaggy Ridge was 'Cutthroat' (i), launched by Chilton’s 18^th Brigade with the aim of capturing the entire feature, including the Kankiryo Saddle. The plan involved the brigade’s three battalions converging on the saddle from three different directions. The 2/12^th Battalion was to advance from Canning’s Saddle, to the east of Shaggy Ridge, and attack the Kankiryo Saddle via two well-defended knolls on the northern end of Shaggy Ridge known as Prothero 1 and 2; the 2/9^th Battalion was to attack to the north along Shaggy Ridge itself; and the 2/10^th Battalion was to advance along Faria Ridge, which lay to the east of Shaggy Ridge and joined it at the Kankiryo Saddle.

All three battalions were to be supported by artillery and Allied aircraft. The 2/10^th and 2/12^th Battalions began their approach marches on 19 January, the 2/12^th Battalion in particular having much precipitous country to traverse and, as a result, not being scheduled to attack for another two days.

On 20 January the 2/10^th Battalion attacked the Japanese positions on Cam’s Saddle in order to fight its way onto Faria Ridge, but was checked by stubborn Japanese resistance.

The operation began in earnest on the following morning with the 2/12^th Battalion clambering up the steep slopes below Prothero 1 and A Company of the 2/9^th Battalion doing the same on the eastern side of Green Snipe’s Pimple, the highest point on both McCaughey’s Knoll and Shaggy Ridge. The unexpected direction of these attacks, up slopes the Japanese obviously regarded as effectively impassable by troops, allowed the Australians quickly to establish a foothold on both features, which had been secured by the end of the day. The Australians now had to withstand several counterattacks supported by persistent and accurate artillery bombardment.

The 2/10^th Battalion’s own artillery support had helped it to force its way onto Faria Ridge earlier in the day and by nightfall it had advanced to within 1,650 yards (1500 m) of the Kankiryo Saddle.

There followed another day of hard fighting on 22 January. The 2/12^th Battalion pushed south along Shaggy Ridge to capture Prothero 2, while the 2/9^th Battalion pushed north to take the rest of MacCaughey’s Knoll. As the two battalions readied themselves to meet the inevitable nocturnal counterattacks, less than 1,100 yards (1000 m) separated them. During the morning of the following day, Australian patrols encountered little opposition and by 12.00 the 2/12^th and 2/9^th Battalions had met and the whole of Shaggy Ridge was in Australian hands.

The 2/10^th Battalion had attacked to both the north and the south along Faria Ridge on 22 January and continued to do so on 23 January. In the north the ridge was held by another strong Japanese position which was not occupied until a time late on the afternoon of 24 January.

By this time, the remaining Japanese stronghold in the area was at the top of the Crater Hill knoll to the north-east of the Kankiryo Saddle. This was the former Japanese regimental headquarters, and its defences were both well-sited and sturdily constructed. It was decided that rather than attack this position, the Australian 18^th Brigade would contain it with patrols before it was pounded with bombs and artillery fire sufficient to inflict casualties so heavy that a final assault could be conducted at minimal cost.

This siege lasted until 1 February, when a company from each of the 2/9^th and 2/10^th Battalions advanced up Crater Hill to find it devastated and unoccupied.

The capture of Shaggy Ridge cost the 18^th Brigade 46 men killed and 147 wounded, and inflicted more than 500 casualties on the Japanese, including 244 confirmed deaths.