Taking place in the Pacific Theatre of World War II, the battle was the first naval action in which the opposing fleets neither sighted nor fired upon one another, attacking over the horizon from aircraft carriers instead.

In launching this war, Japanese leaders sought to neutralize the U.S. fleet, seize territory rich in natural resources, and obtain strategic military bases to defend their far-flung empire.

The navy's general staff and the IJA accepted Inoue's proposal and promoted further operations, using these locations as supporting bases, to seize New Caledonia, Fiji, and Samoa and thereby cut the supply and communication lines between Australia and the United States.

[13] Admiral Isoroku Yamamoto, commander of the Combined Fleet, was concurrently planning an operation for June that he hoped would lure the U.S. Navy's carriers, none of which had been damaged in the Pearl Harbor attack, into a decisive showdown in the central Pacific near Midway Atoll.

The Allies regarded Port Moresby as a key base for a planned counteroffensive, under General Douglas MacArthur, against Japanese forces in the South West Pacific area.

TF 16, commanded by Vice Admiral William F. Halsey and including the carriers Enterprise and Hornet, had just returned to Pearl Harbor from the Doolittle Raid in the central Pacific.

Supporting the Tulagi force was the Covering Group with the light carrier Shōhō, the IJN's four Furutaka /Aoba-class heavy cruisers, and one destroyer, commanded by Rear Admiral Aritomo Gotō.

Bad weather during two attempts to make the delivery on 2–3 May compelled the aircraft to return to the carriers, stationed 240 nmi (280 mi; 440 km) from Rabaul, and one of the Zeros was forced to ditch in the sea.

[29] To give advance warning of the approach of any Allied naval forces, the Japanese sent submarines I-22, I-24, I-28 and I-29 to form a scouting line in the ocean about 450 nmi (520 mi; 830 km) southwest of Guadalcanal.

warship force under MacArthur's command, led by Australian Rear Admiral John Crace and made up of the cruisers HMAS Australia, Hobart, and USS Chicago, along with three destroyers.

[37] A message from Pearl Harbor notified Fletcher that radio intelligence deduced the Japanese planned to land their troops at Port Moresby on 10 May and their fleet carriers would likely be operating close to the invasion convoy.

[38] In the meantime, Takagi's carrier force steamed down the east side of the Solomons throughout the day on 5 May, turned west to pass south of San Cristobal (Makira), and entered the Coral Sea after transiting between Guadalcanal and Rennell Island in the early morning hours of 6 May.

Takagi detached his two carriers with two destroyers under Hara's command to head towards TF 17 at 20 kn (23 mph; 37 km/h) in order to be in position to attack at first light the next day while the rest of his ships completed refueling.

[44] Late on 6 May or early on 7 May, Kamikawa Maru set up a seaplane base in the Deboyne Islands in order to help provide air support for the invasion forces as they approached Port Moresby.

[46] Believing Takagi's carrier force was somewhere north of him, in the vicinity of the Louisiades, beginning at 06:19, Fletcher directed Yorktown to send 10 Douglas SBD Dauntless dive bombers as scouts to search that area.

[56] Attacking first, Lexington's air group, led by Commander William B. Ault, hit Shōhō with two 1,000 lb (450 kg) bombs and five torpedoes, causing severe damage.

At 12:10, using a prearranged message to signal TF 17 on the success of the mission, Lexington SBD pilot and squadron commander Robert E. Dixon radioed "Scratch one flat top!

Choosing his most experienced crews, including Takahashi, Shimazaki and Lieutenant Tamotsu Ema, at 16:15 Hara launched 12 dive bombers and 15 torpedo planes with orders to fly on a heading of 277° to 280 nmi (320 mi; 520 km).

[64] At 17:47, TF 17 – operating under thick overcast 200 nmi (230 mi; 370 km) west of Takagi – detected the Japanese strike on radar heading in their direction, turned southeast into the wind, and vectored 11 CAP Wildcats, led by Lieutenant Commanders Paul H. Ramsey and James H. Flatley, to intercept.

Several of the Japanese dive bombers encountered the U.S. carriers in the darkness, around 19:00, and briefly confused as to their identity, circled in preparation for landing before anti-aircraft fire from TF 17's destroyers drove them away.

The invasion convoy, Gotō, and Kajioka steered towards a rendezvous point 40 nmi (46 mi; 74 km) east of Woodlark Island to await the outcome of the carrier battle.

[74] Yorktown's dive bombers, led by William O. Burch, reached the Japanese carriers at 10:32, and paused to allow the slower torpedo squadron to arrive so that they could conduct a simultaneous attack.

[76] With her flight deck heavily damaged and 223 of her crew killed or wounded, having also suffered explosions in her gasoline storage tanks and an engine repair workshop destroyed, Shōkaku was unable to conduct further aircraft operations.

At 15:00, Takagi notified Inoue his fliers had sunk two U.S. carriers – Yorktown and a "Saratoga-class" – but heavy losses in aircraft meant he could not continue to provide air cover for the invasion.

Inoue, whose reconnaissance aircraft sighted Crace's ships earlier that day, recalled the invasion convoy to Rabaul, postponed MO to 3 July, and ordered his forces to assemble northeast of the Solomons to begin the RY operation.

At 01:00 on 10 May, hearing no further reports of Japanese ships advancing towards Port Moresby, Crace turned towards Australia and arrived at Cid Harbor, 130 nmi (150 mi; 240 km) south of Townsville, on 11 May.

On 14 May, Nimitz, having obtained intelligence concerning the Combined Fleet's upcoming operation against Midway, ordered Halsey to make sure that Japanese scout aircraft sighted his ships the next day, after which he was to return to Pearl Harbor immediately.

The results of the battle confirmed the low opinion held by the Japanese of U.S. fighting capability and supported their overconfident belief that future carrier operations against the U.S. were assured of success.

In H. P. Willmot's words, the commanders "had to contend with uncertain and poor communications in situations in which the area of battle had grown far beyond that prescribed by past experience but in which speeds had increased to an even greater extent, thereby compressing decision-making time.

"[115] Because of the greater speed with which decisions were required, the Japanese were at a disadvantage as Inoue was too far away at Rabaul to effectively direct his naval forces in real time, in contrast to Fletcher who was on-scene with his carriers.