What does half a league mean?

"Half a league" is a nautical term that refers to a distance of approximately 1.5 miles (or about 2.4 kilometers), as a league is traditionally defined as three miles. The phrase is famously used in Alfred Lord Tennyson's poem "The Charge of the Light Brigade" to evoke the idea of a specific distance traveled by soldiers. In general, it conveys a sense of journey or movement over a defined distance.