Charles Bridgeman (1690 - 1738)
(http://faculty.bsc.edu/jtatter/haha1.jpg)
Charles Bridgeman is credited with moving the French ha ha, which is pictured above, to England (http://oxfordindex.oup.com/view/10.1093/oi/authority.20110803095527782). The purpose of the ha ha was to give the illusion that the garden goes for miles: to let the eye wander from the estate outward without interruption. The ha ha also kept the wanted animals in the garden space, and didn't allow the unwanted animals to get in. Bridgeman was working at Stowe in 1713, however he wasn't appointed royal gardener till 1726. Bridgeman's work at Stowe hints at reducing the dominance of the central axis, and instead he emphasises the complex network of pathways that enter-twined the garden together. His work at Stowe and Rousham highlight his contribution to freeing of the English garden from the rigid geometry in the French and Dutch gardens (http://brookmans.com/environment/gobions/ch3.shtml).
William Kent (1684-1748)
(http://www.gardenhistorymatters.com/2012/03/e-is-for-english-landscape-garden.html)
William Kent (pictured above) took Bridgemen's work of 'freeing' of the English garden from the French and Dutch styles further. He de-formalised the English garden further to create ideal landscapes and picturesque views (http://www.gardenhistorymatters.com/2012/03/e-is-for-english-landscape-garden.html). Kent's motto was “Nature abhors straight lines," which parallels with Bridgeman's views of reducing the dominance of the main axis. For example, straight paths were carefully avoided, and all water features, including fountains were tabooed. The only water that remained in the garden were lakes with irregular banks, or a river that flowed in a curved pattern in the ground. Kent's scheme of light and shade was expressed in bushes and trees; the trees were allowed to grow freely, but were planted very schematically. The lawn, which was an important part of the English garden, was required by the theorists of the early 18th century to save as a carpet contrasting in color with groups of trees and bushes (http://www.gardenvisit.com/history_theory/library_online_ebooks/ml_gothein_history_garden_art_design/english_landscape_garden_designers).
Lancelot "Capability" Brown (1716-1783)
(http://www.gardenhistorymatters.com/2012/03/e-is-for-english-landscape-garden.html)
Just like Kent and Bridgeman, Brown had a "passion for rooting out the 'unnatural and bad taste' of the old style" (http://www.gardenvisit.com/history_theory/library_online_ebooks/ml_gothein_history_garden_art_design/english_landscape_garden_designers). Brown incorporated, and was the original advocate, of Hogarths "line of beauty," which he had in almost every part of his garden. The path went around the whole park and was called "the belt," which was meant to give the estate an effect of greater size. Brown was the first to give movement to the lake, and his chief strength was his water plans. He was nicknamed "Capability" Brown because he was always talking about the “capabilities” of his garden grounds. Flowers did not have a place in this English garden; however, they took place in the background (kitchen-gardens), and had been allowed to keep to their own enclosures (http://www.gardenvisit.com/history_theory/library_online_ebooks/ml_gothein_history_garden_art_design/english_landscape_garden_designers).
Each of the three designers had an immense influence on the English Landscape garden: from moving it from the ridged French influenced structure, to the loose English structure.