Salisbury Plain is a chalk plateau in central southern England covering 300 square miles (780 km2). It is part of the Southern England Chalk Formation and largely lies within the county of Wiltshire, with a little in Hampshire. The plain is famous for its rich archaeology, including Stonehenge, one of England's best known landmarks. Largely as a result of the establishment of the Army Training Estate Salisbury Plain (ATE SP), the plain is sparsely populated and is the largest remaining area of calcareous grassland in north-west Europe. Additionally the plain has arable land, and a few small areas of beech trees and coniferous woodland.
The boundaries of Salisbury Plain have never been truly defined, and there is some difference of opinion as to its exact area. The river valleys surrounding it, and other downs and plains beyond them loosely define its boundaries. To the north the scarp of the downs overlooks the Vale of Pewsey, and to the north west the Bristol Avon. The River Wylye runs along the south west, and the Bourne runs to the east. The Avon runs through the eastern half of the plain and to the south the plain peters out as the river valleys close together before meeting at Salisbury. From here the Avon continues south to the English Channel at Christchurch, Dorset.
Ludlow was born in Maiden Bradley, Wiltshire, the son of Sir Henry Ludlow of Maiden Bradley and his wife, Elizabeth, daughter of Richard Phelips of Montacute, Somerset. He matriculated at Trinity College, Oxford in September 1634 and graduated in 1636. He was admitted to the Inner Temple in 1638.