Sir Norman Leslie acquired Fythkil c. 1282 and renamed it Leslie after his family estates in Aberdeenshire. In 1457, George Lord Leslie of Leven was created 1st Earl of Rothes, with estates in Fife, Perth, Aberdeen and Elgin. The earliest evidence of a house on this site dates from 1667–72, when John Mylne the younger and Robert, his nephew, with advice from Sir William Bruce designed the 'Palace of Rothes' (Defoe 1724-7, p.778-9; Gifford 1992, p.306-7; Colvin 1995, p.677-8). It was built for John, 7th Earl and 1st Duke of Rothes (d. 1681) a distinguished statesman and close supporter of Charles II, he carried the sword at the coronation of Charles II in Scone and was taken prisoner after the Battle of Worcester. The quadrangular house was attributed to Sir William Bruce by Defoe who described it as 'the Glory of the Place, and indeed of the whole Province of Fife'. Said to be similar to Holyrood Palace, it was built around a court, with a gallery.
Evidence of the palace's designed landscape shows it situated on a haugh with the River Leven flowing to the south and the Lothrie Burn to the north (Roy 1747-55). Formal gardens included a series of terraces, grass platts and a water garden, leading from the house south to the River Leven. Woodland, extending over the area known as South Wood (1913, O.S. 6"") along the south banks of the Leven, was cut by diagonal and transverse paths. Beyond, a series of square parks were laid out between avenues and rides, directed north-south. To the north of Leslie House a series of parks were laid out between two avenues orientated east-west.
Macky' s description accords with this map evidence and amplifies our knowledge:
'It stands in the middle of a park, surrounded with a stone wall, of six miles in circumference, on a point of land where two rivers washeth it on each side, and join in one at the end of the gardens: It is extremely well planted with full grown trees, that at a distance seem to be a large wood; there's a noble parterre to east, cut out into green slopes, adorn'd with evergreens, that reacheth to the point where these two rivers meet. And from this parterre on the south of the house, is a long terrace walk, and under it five several terraces, to which you descend by stately stairs, to another square garden by the river side, with a water work in the middle, and round which the present earl designs to carry the river. You enter the palace by two spacious courts, with a pavilion at each end of the first court; the house is a large square with a paved court in the middle ' (Macky 1723, p.72).
Following a fire on 28th December 1763, the north, south and east ranged were demolished and the west wing was reconstructed between 1765–7 for John, 11th Earl of Rothes (d. 1773), who inherited in 1767. The present house consists of this reconstructed west wing, a much smaller residence.
A 1775 estate survey depicts the landscape as modified by the 11th Earl, and when inherited by Countess Jane Elizabeth Leslie (d. 1810), his eldest sister (Bell 1775). The pavilions, described by Macky, flanked an outer entrance court leading into the West Avenue. The latter postdates the 1750s and was laid out to complement the reconstruction of the west wing as the house (Roy 1747-55). The West Avenue terminated in a rond point with a central feature, possibly a statue, before turning northwards, through a plantation, to meet the road leading eastwards from Leslie. The 'Back Court' overlay the East Parterre, although it did not reach to the 'point where these two rivers meet' (Macky 1723, p.72). The East Avenue extending to Cowdam, a hamlet on the boundary of the designed policies, was a prominent feature (Roy 1747-55). A major component of the formal gardens, lying to the south of the garden terraces on the south front was the water garden – 'a water work' as described by Macky. By 1775 an expansive walled garden had been built to the north of the house, on the north banks of the Lothrie Burn. Comparison of surveys suggests that this is attributable to the 11th Earl (Roy 1747-55; Bell 1775).
There appear to have been few landscape changes during the ownership of George William, 13th Earl of Rothes (succeeded in 1810, d. 1817) or his eldest daughter, Henrietta Anne, Countess of Rothes (d. 1819). The impetus for 19th-century estate improvements seems to belong to George William Evelyn, 15th Earl of Rothes (1809-86), who inherited the estate in 1819. Sometime between 1810 and the 1890s, the West Drive leading to the West Lodge was extended and informalised; other lodges were built (Forester's Lodge, Mains Lodge) or improved (South Lodge, East Lodge). The East Avenue was extended to form a new drive leading in from the outer policies. Other estate farms and land improvements date to this period (1893, OS 25"").
Following the death of the 15th Earl in 1886, the estate was inherited by his daughter, Henrietta Anderson Morshead, Countess of Rothes (1832-86), and then passed to her aunt, Mary Elizabeth (1811-93), 17th Countess of Rothes. In 1919, Leslie House was sold to Sir Robert Spencer Nairn, who gifted it to the Church of Scotland in 1952, for use as an Eventide Home. During his residence Nairn carried out considerable building work, including estate cottages in the vicinity of Leslie Mains; the Duke's Lodge and work to the West Lodge. Within the gardens, along the top terrace and below the Long Walk, flower-beds enclosed by low rubble walls were built.
Despite the loss of the South Parks for Glenrothes' housing, some of the estate's place-names survive and have been transferred to housing estates, e.g.'South Parks' and 'Macedonia', which were estate farms (Martin 1810) 'Auchmuty' and 'Cadham', which were hamlets (Achmuty, Cowdam, Roy 1747-55)
Glenrothes trunk road system has fragmented the designed landscape; the junction of Leslie Road (A911) with Western Avenue (B969) has truncated the East Avenue and bridging the River Leven has divorced Forester's Lodge and East Lodge from the core landscape. The 'garden by the riverside, with a waterwork in the middle' has reverted to boggy haughland. Nevertheless, the core structure of the designed landscape is relatively intact; the stone walls of the West Court survive, as do the main framework of the East Parterre, the Long Walk and the formal terraces south of the house. Currently, following the closure of the nursing home the house is being marketed by the Church of Scotland (2004).