Picket (military) in the context of N. C. Wyeth

The Battle of Germantown was a major engagement in the Philadelphia campaign of the American Revolutionary War. It was fought on October 4, 1777, at Germantown, Pennsylvania, between the British Army led by Sir William Howe, and the American Continental Army under George Washington.

After defeating the Continental Army at the Battle of Brandywine on September 11, and the Battle of Paoli on September 20, Howe outmaneuvered Washington, seizing Philadelphia, the capital of the United States, on September 26. Howe left a garrison of some 3,000 troops in Philadelphia, while moving the bulk of his force to Germantown, then an outlying community to the city. Learning of the division, Washington determined to engage the British. His plan called for four separate columns to converge on the British position at Germantown. The two flanking columns were composed of 3,000 militia, while the center-left, under Nathanael Greene, the center-right under John Sullivan, and the reserve under Lord Stirling were made up of regular troops. The ambition behind the plan was to surprise and destroy the British force, much in the same way as Washington had surprised and decisively defeated the Hessians at Trenton. In Germantown, Howe had his light infantry and the 40th Foot spread across his front as pickets. In the main camp, Wilhelm von Knyphausen commanded the British left, while Howe himself personally led the British right.

The Battle of Jutland (German: Skagerrakschlacht, lit. 'Battle of the Skagerrak') was a naval battle between Britain's Royal Navy Grand Fleet, under Admiral Sir John Jellicoe, and the Imperial German Navy's High Seas Fleet, under Vice-Admiral Reinhard Scheer, during the First World War. The battle unfolded in extensive manoeuvring and three main engagements from 31 May to 1 June 1916, off the North Sea coast of Denmark's Jutland Peninsula. It was the largest naval battle and only full-scale clash of battleships of the war, and the outcome ensured that the Royal Navy denied the German surface fleet access to the North Sea and the Atlantic for the remainder of the war. Germany avoided all fleet-to-fleet contact thereafter. Jutland was also the last major naval battle, in any war, fought primarily by battleships.

Germany's High Seas Fleet intended to lure out, trap, and destroy a portion of the British Grand Fleet. The German naval force was insufficient to openly engage the British fleet. This was part of a larger strategy to break the British blockade of Germany and allow German naval vessels access to the Atlantic. Britain's Royal Navy pursued a strategy of engaging and destroying the High Seas Fleet, thereby keeping German naval forces contained and away from Britain and her shipping lanes. The Germans planned to use Vice-Admiral Franz Hipper's fast scouting group of five modern battlecruisers to lure Vice-Admiral Sir David Beatty's battlecruiser squadrons into the path of the main German fleet. They stationed submarines across the likely routes of the British ships. However, the British learned from signal intercepts that a major fleet operation was likely, so on 30 May, Jellicoe sailed with the Grand Fleet to rendezvous with Beatty, passing over the German submarine picket lines while they were unprepared. The German plan had been delayed, causing further problems for their submarines, which had reached the limit of their endurance at sea.

A radar picket is a radar-equipped station, ship, submarine, aircraft, or vehicle used to increase the radar detection range around a nation or military (including naval) force to protect it from surprise attack, typically air attack, or from criminal activities such as smuggling. The term 'picket' is an old military term for a sentry placed forward of a defensive line, in order to provide an advanced warning. By definition a radar picket must be some distance removed from the anticipated targets to be capable of providing early warning. Often several detached radar units would be placed in a ring to encircle a target to provide increased cover in all directions; another approach is to position units to form a barrier line.

Radar picket units may also be equipped to direct friendly aircraft to intercept any possible enemy. In British terminology the radar picket function is called aircraft direction. A ship performing this function is termed a fighter direction ship. Airborne radar pickets are referred to as Airborne early warning and control (AEW&C) or simply airborne early warning (AEW), depending on capabilities.