In April 1915 the Sqn moved to Hounslow where it remained for a month before moving to Swingate Down near Dover. During this time the Sqn found itself tasked with home defence duties, but continued to train for deployment to France. Around this time the Sqn began to re-equip with additional BE2c aircraft. In September 1915 Major Edgar Ludlow-Hewitt took command of 15 Sqn. However, his tenure was to be fairly short, as in November 1915 he was succeeded by Major H de L Brock, DSO.

In March 1916 the Sqn moved to Vert Galand, on the Somme, to become part of 3rd Wing. By an ironic twist of fate, Lieutenant Colonel Edgar Ludlow-Hewitt, MC, a previous OC 15 Sqn, now commanded the 3rd Wing. This attachment proved to be a short-lived as 3 weeks later the Sqn moved to Marieux. 15 Sqn undertook many reconnaissance and photographic missions in preparation for the Somme offensive, which commenced on 1 July 1916. Army commanders acknowledged the role played by aerial reconnaissance at the end of the first phase of the Battle, praising the quality of the work, which enabled the destruction of many German positions. The Sqn continued to undertake reconnaissance patrols and aerial photographic sorties through to October that year.

It was during a period of intense fighting the following year, that a new British military force was created. On 1 April 1918 the Royal Naval Air Service and the RFC amalgamated to form the RAF. The 1918 spring offensive was a busy period for 15 Sqn, with constant flying and several quick moves. As the German offensive was held, the squadron, now at Vert Galand, returned to its more traditional aerial reconnaissance work. This continued until the final offensive in the autumn of 1918, when the Sqn also took on the unusual task of dropping boxes of ammunition by parachute to front line troops.

Air Officer Commanding-in-Chief Bomber Command, Air Marshal Sir Arthur Harris felt that he needed to show the politicians the mettle of the men under his command, and prove they could get the job done. He therefore formulated an operation, simply known as the ‘Thousand Plan’ in which he intended to deploy 1000 bombers to one target, on the same night. One of the senior officers who assisted Harris was Group Captain Samuel Elworthy, who had served with XV Sqn between 1935 and 1937. Two possible dates for the attack were selected, as were two targets. On the morning of 30 May 1942, Air Marshal Harris made his decision; the target was Cologne and ‘his boys’ would go that night. XV Sqn detailed twelve Stirling bombers for the raid. Two of the Sqn’s aircraft were forced to return early due to mechanical problems, but the ten remaining aircraft completed their task and returned safely to base. One of the ten was intercepted by a German night-fighter, but managed to evade four separate attacks and return home without injury. Two nights later, on 1 June, Harris ordered another 1000 bomber attack, this time against Essen. Of the eleven sqn aircraft that took part in the raid, two returned early with electrical and bomb release malfunctions.

On the night of 1 May 1944 a Lancaster recently delivered to the Sqn was detailed for an attack against railway targets at Chambly, northern France. The aircraft carried the serial LL806 and was coded LS-J “Jig”. There was nothing to set this aircraft apart from the others on the Sqn, but as time went by the crews deemed “Jig” to be lucky. Some aircraft failed to return from their first mission, whilst others managed to scrape by to complete a tour of operations, but “Jig” kept on flying. It was to become the Sqn’s most notable Lancaster bomber. LS-J went on to carry out a total of 134 bombing operations before being retired in December 1945.

Increasingly the squadron became involved in the battle against the V-1s, bombing the sites in northern France and returning to daylight operations once more after D-Day. XV Sqn now became a specialized bombing squadron, equipped with 'G-H' to enable it to fly precision blind bombing by day and night, its aircraft so equipped being distinguished by two yellow bars across the fins. In September there was a resumption of strategic bombing, and there was no let-up until the squadron's final attack on 22 April 1945. It then launched into Operation 'Manna' and ‘Exodus’ missions.

‘Manna’ missions were needed because the Dutch railway system had ceased to function after the efforts of Bomber Command and the Dutch resistance. With no supplies getting through to various parts of Holland it was agreed to allow food and supplies to be dropped to the beleaguered Dutch. The supplies were dropped from low level in special panniers.

14 November 1950 saw the Sqn’s association with the Lincoln bomber draw to a close, when it relinquished the last of its aircraft. Two weeks later the Sqn was disbanded, but was immediately reformed again at Marham, Norfolk, in preparation for conversion to a new aircraft.

It was whilst XV Sqn was equipped with Washington bombers that a very poignant event in the Sqn’s history occurred. On 16 March 1951 Sqn aircraft flew for the last time displaying the code letters ‘LS”, which had been adopted back in August 1939. The new scheme for the aircraft was a natural metal finish, adorned with only the RAF roundel, fin flash and serial designation.

In January 1952 it was announced that, having completed twenty-five years service to the Crown and as a mark of the Monarch’s gratitude, the Sqn was to be presented with a Sqn Standard, on which it could display its battle honours. The pride and jubilation of receiving this honour was overshadowed less than a month later when, on 6 February, His Majesty King George VI passed away.

In February 1955 the Sqn moved to Honington, Suffolk. It continued a number of training exercises from Honington, including ‘Lone Ranger’ exercises. These missions enabled crews to practice navigational procedures by flying to overseas locations. Whilst, initially, the ‘target’ locations had been in Germany, Gibraltar and Libya, the number was increased to include areas in the Eastern Mediterranean and the Middle East.

A few days after the Royal Reviews, the British Government despatched a military force to the Eastern Mediterranean. This was due to the nationalisation of the Anglo-French controlled Suez Canal Company by the Egyptain President, Colonel Gamel Nasser. With an escalation of the political situation, XV Sqn was deployed to Nicosia, Cyprus, as part of ‘Operation Accumulate’ in October 1956. During six days of fighting, the Sqn undertook thirty-seven operational missions, dropping more bombs than any other Sqn.

During the 1950s, the British Government had been developing a nuclear deterrent. For the RAF this meant the arrival of the ‘V’ bomber force, which comprised three new aircraft known as the Vulcan, Valiant and Victor, all capable of delivering nuclear bombs.

It was with Handley Page Victor B1 bombers that XV Sqn was re-formed, at Cottesmore, on 1 September 1958. As a rapid response to any hostile threat was vital, the Sqn trained hard to achieve the goal of getting four aircraft airborne in under four minutes from receiving a threat warning. It was a goal that, once achieved, had to be continually practiced. Fortunately these aircraft were never engaged in the type of action for which they were designed. However, the futuristic looking Victor bombers were often seen in the skies around the world, engaged in military exercises, training, air displays and good will visits both at home and abroad.

On 1 October 1970 the Sqn numberplate and crest were resurrected when XV Sqn was re-formed at Honington. The Sqn was equipped with the Buccaneer S2B, which had originally been developed as a Naval aircraft, but was later modified for use by the RAF. As no dual-controlled version of the Buccaneer existed, a Hawker Hunter T7A two-seat trainer was fitted with instruments that replicated that of the Buccaneer, so that dual pilot training could be given.

In January 1971, the Sqn officially became part of Royal Air Force Germany (RAFG), when it relocated to Laarbruch, West Germany. Before its departure to Europe approval was given for each Sqn aircraft to be adorned, as on previous occasions, with the Roman numerals ‘XV’ on top of the tail fin. The one exception to this was the Hawker Hunter, which carried the white numerals on the fuselage.

The Sqn’s 60th Anniversary was marked, amongst other things, with the issue of a special First day Cover. The envelopes, which bore 30pfg Deutsche Bundespost stamps, were illustrated with a BE2c, the Stirling bomber ‘MacRobert’s Reply’ and a Buccaneer. These covers were flown on a route covering Laarbruch, Wyton, Brest, Wyton, Laarbruch the same course taken from Wyton by the Stirling bombers in 1941 when the Sqn attacked German warships in Brest harbour.

In June 1983 XV Sqn began to take delivery of its first Panavia Tornado GR1 aircraft. On 1 September 1983 XV Sqn officially became the first RAFG Tornado Sqn. Following a NATO Tactical Evaluation (TACEVAL) in June 1984 the Squadron was declared operational in the strike (nuclear) role. The Sqn then became attack operational in January 1985, it’s 70th anniversary year.