Robert Watson-Watt carries out a demonstration near Daventry which leads directly to the development of radar in the United Kingdom.

Sir Robert Alexander Watson-Watt was a British radio engineer and pioneer of radio direction finding and radar technology.

Daventry is a market town and civil parish in the West Northamptonshire unitary authority area of Northamptonshire, England, close to the border with Warwickshire. At the 2021 Census, Daventry had a population of 28,123, making it the sixth-largest town in Northamptonshire.

Radar is a system that uses radio waves to determine the distance (ranging), direction, and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain. The term RADAR was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term radar has since entered English and other languages as an anacronym, a common noun, losing all capitalization.

February 26 is the 57th day of the year in the Gregorian calendar; 308 days remain until the end of the year.