The 1st Airborne Division consisted of three infantry brigades and assorted support units, such as artillery, engineers, pathfinders, etc. Due to the insufficient number of transport aircraft available, the First Lift, on Sunday 17th September, would see only the following units transported to Arnhem: the 1st Parachute Brigade, the glider-borne 1st Airlanding Brigade (less two companies of the 2nd South Staffordshires), Major-General Urquhart's Divisional Headquarters, and approximately half of the Divisional units, including two of the three artillery batteries of the 1st Airlanding Light Regiment, and the 1st Airborne Reconnaissance Squadron.
The three drop and landing zones used for the First Lift, DZ-X, LZ-S and LZ-Z, were all situated very close to each other, between six and eight miles west of Arnhem. Twenty minutes before the main formation were due to arrive, the pathfinders of the 21st Independent Parachute Company were to drop on each of the zones to lightly secure and mark them with their Eureka beacons. The gliders of the 1st Airlanding Brigade were then to land on LZ-S, followed twenty minutes later by Headquarters and the Divisional Units on LZ-Z, and finally, half an hour after them, the 1st Parachute Brigade on DZ-X.
The drop and landing zones for the Second Lift were to be protected overnight by the 1st Airlanding Brigade, with the remainder of the Division established in the general area around the village of Wolfheze, bordering LZ's S and Z. Meanwhile the two thousand-strong 1st Parachute Brigade, commanded by Brigadier Lathbury, were to capture Arnhem Bridge and defend it until reinforced by the remainder of the Division.
As the Brigade was to land on a drop zone eight miles from their objective, Lathbury knew that it would take many hours for his men to reach Arnhem on foot, by which time the enemy would be alerted and may likely have ordered the demolition of the Bridge. It was therefore essential that it be seized at the earliest opportunity. Under normal circumstances a coup de main raid would have been attempted, whereby a small number of paratroopers or glider troops would land alongside the objective and to capture and hold it until more substantial forces could arrive to relieve them. The Royal Air Force, however, refused to land any troops so close to Arnhem, and so Lathbury sought an alternative. His solution was to take Major Gough's 1st Airborne Reconnaissance Squadron under his command and charge them with undertaking a coup de main. This unit, consisting of one hundred and eighty men, were all mounted on Jeeps which were vulnerable to enemy fire but armoured with powerful twin-Vickers "K" Machine Guns. Although completely unsuited to the purpose, the Squadron was expected to face only minimal opposition and so should have little difficulty in racing to the Bridge, as soon as their vehicles had been unloaded from their gliders, and holding it until the leading elements of the 1st Parachute Brigade arrived several hours later.
The 2nd Parachute Battalion, under the commander of Lieutenant-Colonel Frost, the most experienced battalion commander in the Division, were to advance on Arnhem alongside the riverbank, codenamed the Lion Route, and capture the Railway Bridge, four miles to the west of Arnhem, and then the pontoon and main road bridge in the town itself. Proceeding along a different path, the Utrechtseweg main road, codenamed the Tiger Route, Lieutenant-Colonel Fitch's 3rd Battalion were to reinforce Frost's positions around the Bridge, whilst Lieutenant-Colonel Dobie and his 1st Battalion headed along the Amsterdamseweg, the Leopard Route, to secure an area of high ground to the north of Arnhem, overlooking a road down which German reinforcements were expected to come.
On the morning of the second day, Brigadier Hackett and his 4th Parachute Brigade would arrive on DZ-Y, ten miles west of Arnhem, together with the remainder of the 1st Airlanding Brigade and the Divisional units. As soon as these troops were assembled, the whole Division would then march to Arnhem, relieve the 1st Parachute Brigade and establish a wide defensive perimeter around Arnhem and Oosterbeek.
Finally, on the third day, Major-General Sosabowski and his 1st Polish Independent Parachute Brigade Group would land their heavy glider-borne equipment on LZ-L, five miles to the west of Arnhem, whilst their parachutists jumped over DZ-K, a mile to the south of Arnhem Bridge. This latter zone was the same as that which had been denied to the 1st Parachute Brigade on the first day for the use of a coup-de-main raid, but the Royal Air Force agreed to drop the Poles here because it was assumed that the 1st Airborne Division would have cleared Arnhem of flak defences by this time, and also that the 2nd British Army would have arrived and cleared the emplacements around Deelen Airfield. If, for whatever reason, Sosabowski landed on DZ-K and discovered that the Bridge was still in enemy hands, he was ordered to take it himself.
All being well, however, the Polish Brigade would occupy positions to the east of Arnhem whilst the 4th Parachute Brigade secured the north of the town and the high ground earlier seized by the 1st Parachute Battalion. The 1st Airlanding Brigade and 1st Airlanding Light Regiment were to establish themselves in and around Oosterbeek, four miles to the west, whilst the 1st Parachute Brigade were withdrawn into reserve, holding the Bridge itself and the land to the south of the Rhine. Following a successful outcome to Operation Market Garden, the 1st Airborne Division were to remain in the area to act as ordinary ground troops, and they were to be joined by the air-transportable 52nd (Lowland) Division, who were to be flown to Deelen Airfield as soon as it was secured.
The main weaknesses of the plan outlined above were the large distances from the drop zones to the Bridge, the fact that it would require three lifts over three days to get the Division onto the battlefield, and the belief that there would be very little enemy to oppose the landings. There was, however, no evidence available to the Division to suggest that there would be serious opposition in the area and, with this in mind, it was believed that the plan would work very well.