The main lake came into being by accident. In 1870, Alfred and Arthur East, the owners of Longstock House, dredged gravel from the banks of the River Test in order to build a private road to the property, creating the lake in the process.

When the Easts sold the Longstock Estate in 1914, Reginald Beddington, the son of the new owner, decided to make an aesthetic feature of the water. In the 1920's, it was channelled into a central canal flanked by two small lakes and the margins were planted with perennial beds.

The water garden you see now, however, was only created after John Spedan Lewis acquired the estate in 1946. With the help of botanist Terry Jones, whose keen eye for colour was invaluable when it came to selecting inspired combinations of plants, Spedan Lewis began an ambitious plan of redevelopment. He trebled the garden in size, adding a wealth of detail to the main lake with promontories, islands and bridges. The water-logged soil meant all the work had to be done by hand, and it was ten long years before the project was completed.

Longstock's first head water gardener, Jim Saunders - originally Spedan Lewis's butler - organised the digging and the garden remained under his stewardship until his retirement in 1983. Today there is still a strong sense of continuity: despite some damage caused by the storms of 1987 and 1990, much of Spedan Lewis's original concept remains unchanged.