'Pegasus' was an Allied pair of operations ('Pegasus I' and 'Pegasus II') after the failure of 'Market' and 'Garden' in order to recover across the Nederrijn (Lower Rhine) river the survivors of Major General R. E. Urquhart’s British 1^st Airborne Division who had escaped capture by the Germans and sought shelter in the forests around Ede to the west of Arnhem (22/23 October and 18/19 November 1944).

The actual numbers of the men involved in the fighting in and around Arnhem are uncertain, but it is believed that somewhat more 10,400 men fought in the area to the north of the Nederrijn river, and in 'Berlin' (iii) between 2,400 and 2,500 of them managed to withdraw safely to the southern bank, which left some 7,900 men on the northern bank. Almost 1,500 of these latter were killed, 6,000 were captured, and 500 hid in the woods and villages near the river.

Major Digby Tatham-Warter of the Parachute Regiment had escaped from a German hospital as early as 21 September and, after hiding for a week, was contacted by the Dutch resistance with a request for assistance in Ede. Early in October Tatham-Warter was joined by Brigadier G. L. Lathbury, commander of the 1^st Parachute Brigade, and Lieutenant Colonel D. Dobie, commander of the 1/Parachute, and the three men created a clandestine brigade headquarters. Tatham-Warter established contact with Lieutenant Gilbert Kirschen of the Belgian SAS, who arranged supply drops of weapons, uniforms and supplies for the growing number of British troops hiding in the area. Piet Kruijff, head of the local resistance group, had been organising the evaders into safe houses in Ede. Soon there were more than 80 men in the town, which became so full that Kruijff had to start accommodating new arrivals in nearby Reemst where, by the time of 'Pegasus I', there were 40 men. At first these evaders and the resistance hoped that the Allied offensive would be quickly resumed and liberate them: Tatham-Warter even made plans for operations against the Germans when Lieutenant General Sir Miles Dempsey’s British 2^nd Army started to cross the Rhine river.

In October, however, Kirschen had to tell the resistance that there were no plans for an attack to the north of the Nederrijn within the foreseeable future. As the presence of so many evaders was already imposing severe strains on the resistance and exposing to severe risk the civilians hiding them, the decision was taken to evacuate the men as soon as possible. The 'HQ in hiding' was already in contact with the 2^nd Army’s escape organisation, based in Nijmegen, and after swimming across the Nederrijn river on the night of 16 October and reaching the Allied lines, Dobie was able to make further arrangements. Dobie contacted Lieutenant General B. G. Horrocks’s XXX Corps and Major General Maxwell D. Taylor’s US 101^st Airborne Division, which both approved the plan. Dobie was also able to speak to Tatham-Water by telephone, and the two drafted a plan for the evaders' escape. Dobie suggested a location on the river to the west of Renkum for the crossing. A rendezvous and route to the river from the north were fixed, and it was arranged that the men would be met on the northern bank by men of the Canadian Royal Engineers of the XXX Corps escorted by a party of the US 506^th Parachute Infantry. To provide guidance for the evaders, the crossing point would be marked by tracer fire from a Bofors gun. The US paratroopers undertook patrols to the north of the river and tracer fire was sent across the river on several nights to disguise the actual purpose of the operation, which was scheduled for 23/24 October.

On 20 October the Germans ordered residents of nearby villages to leave their homes within two days and, once it had been appreciated how great a level of confusion would result, the operation was brought forward to the night of 22/23 October. The men were brought together from their various places of concealment to a rendezvous in the woods just to the north of the river. There were many Germans in the area after the fighting in Arnhem, and the men assembled at a spot only 500 yards (460 m) from German machine gun positions. By the fall of night 139 men had assembled: these were mostly men of the 1^st Airborne Division, but there was also one trooper of Major General James M. Gavin’s US 82^nd Airborne Division, a number of downed aircrew, some Dutch civilians and a few escaped Soviets who wished to join the Allies. The men were organised into platoons, and at 21.00 began to move toward the river. Tatham-Warter believed that the Germans knew of their presence but were unsure of the Allied numbers and, wary of US patrols, kept their distance: even so, there was one contact with a patrol and a brief exchange of fire, but no injuries resulted.

At 24.00 the group reached the river and moved to the crossing point marked by the tracer fire. Once they were in position the evaders used a torch to flash the pre-arranged signal, but then had to wait 20 minutes for the arrival of the boats. On the southern bank Dobie, the engineers and a patrol of the 506^th Parachute Infantry’s Company E had seen the signal and immediately launched the boats, but the evaders were in fact some 450 to 850 yards (410 and 775 m) farther up the river than the arranged crossing point. On disembarking on the northern bank, some of Company E’s men established a small perimeter and others headed to the east to locate the evaders. The latter quickly moved downstream and in the next 90 minutes all but one of them, a Soviet caught by the Germans, were evacuated. The Germans opened fire sporadically and some mortar rounds fell near the crossing, but the fire was inaccurate.

The success of this undertaking prompted the Allies to plan a second attempt as 'Pegasus II'. Unfortunately, though, the operation’s security was compromised at at early stage when a reporter impersonated an intelligence officer and interviewed several escapees, the subsequent news story alerting the Germans who strengthened their patrols along the river. Major Hugh Maguire of the 1^st Airborne Division’s headquarters put in charge of the second undertaking, which was to be essentially a repeat of the first, although 2.5 miles (4 km) farther to east at Heteren, on the evening of 18 November.

Between 130 and 160 men were to be pulled back across the river on this occasion, although this number included a much greater proportion of civilians, aircrew and other non-infantry wholly unused to this sort of operation. Because of the distance from Ede to the crossing point and the need to skirt a German no man’s zone, the route to be used by the main party had a length of about 14 miles (23 km), compared with that of 3.1 miles (5 km) in 'Pegasus I', and would require two days. The main party became scattered on the second of these nights and, while trying to make a short cut, a party led by Major J. Coke of the King’s Own Scottish Borderers stumbled into a German patrol. Several men (perhaps more than 20) were killed in the resulting firefight, and the evaders were forced to scatter. No one was able to make the crossing during that night, but seven men crossed during the next two days. The Germans then undertook an intensive search of the area and captured more of the evaders, and most of the guides provided by the resistance were killed or captured.