The year 1915 ended with an air raid on Salonika, the city in neutral Greece where the Entente allies maintain a beachhead in the Balkans, while the new year has seen frequent harassment attacks launched from their base at Xanthi inside Bulgarian territory. Conducted with small numbers of aircraft dropping small bombs, these joint operations by German and Bulgarian pilots have done little damage, but they have transformed the Macedonian front into a modern air-land-sea battle.

As seen in the above image of a petty officer aiming a 12-pounder gun aboard the HMS Agamemnon, the allies have a great deal of firepower in the water, making the harbor itself a dangerous target. But the same powerful warships are supremely vulnerable to submarine torpedoes while sitting at anchor to provide that air cover, necessitating air and sea reconnaissance against the u-boat threat. Machine guns and field artillery aimed skyward make the military encampments themselves into prickly objectives, but the enemy has dared their fire anyway: one raid eleven days ago even dropped a bomb in the middle of a British battalion, though without effect.

An Albatross reconnaissance plane like the ones used for most of these early raids against the allies at Salonika

Today there is another small raid, this time targeting the front lines of the allied defensive perimeter known as the ‘Birdcage.’ While no one is killed or injured, the event underscores the allies’ vulnerability and challenges their command of the skies. In reprisal, two French airmen fly a 400-mile round-trip mission of their own to drop incendiary bombs on the Bulgarian capital of Sofia on April 23rd. Nor do these attacks go unnoticed in Greece, as newspaper reports make clear. The North Eastern Ensign in Victoria, Australia prints the following wire notice tomorrow morning:

The recent air attacks on Salonika have alarmed the Greek population. Deputies ion the Greek Chamber, representing Salonika, urged the Prime Minister to ensure security against a fresh serial bombardment. They demanded the evacuation of Salonika by the Allies and the removal of ammunition stores. They also urged the Prime Minister to notify Germany that further bombing would be considered to be directed against Greece. The Prime Minister complied with the demands as far as they concerned the Allies.

No withdrawal of forces is pending, however. Instead, both sides do their best to raise the scale of their air power assets in the region despite its remoteness from grander strategic theaters. Already pressed to meet the demands of the Western and Eastern Fronts, Berlin is also obliged to supply the Bulgarian 1st and 30th Flying Sections with everything they need. One Zeppelin has already made a pass at Salonika recently and another will raid the Birdcage in May. During June, the L-71 arrives in Yambol to begin regular harassment attacks on allied bases at the isles of Mudros and Mytiline. Leutnant Rudolf von Eschwege arrives this summer and is assigned to fly the only Fokker Eindecker in the entire theater with reckless abandon across an impossibly-large area of responsibility.

A Short seaplane of the Royal Naval Air Service landing in Salonika harbor during 1916

Meanwhile, the British 17th Squadron arrives the same month with planes built for air combat. They are joined by the 47th Squadron in September, and by the end of the year the RNAS airbase on the island of Thasos will host two wings. Serbian aviators take to the skies as well. Altogether, the allies assemble a total of 160 airplanes of various types around Salonika during 1916, outnumbering the Central Powers ten to one. But while dogfights and bombing missions get all the press, the crucial task for both sides is aerial photography; while the Central Powers search for weaknesses in the allied defenses, the international coalition monitors their movements and begins the planning for the eventual counteroffensive against their enemy’s Balkan flank.

A map of the aerial theater of combat shows the RNAS base on Thasos and the Bulgarian base opened at Drama later this year