There is very little known about the early history of the site at Lathom. it is highly likely that Thomas Stanley carried out major redevolopment works during the 1490s following his rise to power in the post Bosworth years. What was already in existence on the site prior to this is a matter for speculation, but it seems highly likely that there would have previously been a residence on the site for a considerable period of time, though almost certainly not as grand or well defended as Stanley later made it. There are no known surviving paintings of the residence or castle, although a wood carving at Manchester cathedral is thought to be a depiction, showing a central building surrounded by a defensive wall containing a gatehouse and towers at intervals along its length.
At the Battle of Bosworth in 1485, Thomas Stanley was instrumental in the demise of Richard III, thus enabling Stanley's stepson, to take the crown as Henry VII. As the first Earl of Derby, Stanley increased both his wealth and power within England, that power being second only to the King himself. It was during the latter years of the 15th century, that having gained this increase in status, that Lathom was extensively remodelled. Henry VII is known to have visited Lathom and it is thought that it impressed him enough to have influenced the design of Richmond Palace, built on the banks of the Thames. Whilst illustrations of Richmond Palace survive, it is difficult to know with any certainty the degree of similarity it shared with Lathom.
It is likely that Lathom in common with many historic residences, underwent considerable alteration through the centuries. We have to rely on contemporary Civil War accounts later published to find descriptions of Lathom in the mid 17th century. "The History of the Stanley Family" by John Seacombe gives a Civil War period description of Lathom from contemporary accounts thus:
"Standing on a flat moorish, springy and spumous ground, was at the time of the siege encompassed with a strong wall, of two yards thick: upon the wall were nine towers, flanking each other, and in every tower were six pieces of ordnance that played three one way and three the other. Without the wall, was a moat eight yards wide, and two yards deep; upon the brink of the moat, between the wall and the graff, was a strong row of palisadoes, and to add to these securities, there was a high tower called the Eagle Tower, in the midst of the house, surrounding all the rest; and the gatehouse was also a strong and high building with a strong tower on each side of it; and in the entrance to the first court upon the tops of these towers were placed the best and choicest marksmen. Before the house, to the south and south-west, there is a rising ground so near as to overlook the top of it, which falls so quick that nothing planted against it on those sides can touch it, further than the front walls. And on the north and east sides there is another rising ground, even to the edge of the moat, and then falls away so quick that you can scarce, at the distance of a carbine shot, see the house over the height’.
As Lathom had become an iconic symbol of Royalist power and considering the humiliation suffered by the Paliamentarian forces during the first siege, it is no wonder that following the second siege in 1645 they went to great lengths to ensure that Lathom was slighted and would not return to its former glory.
Following the Restoration in 1660, Lathom House was returned to the Stanleys. In 1730 it passed by the marriage of Henrietta Stanley to John Ashburnham, 3rd Baron Ashburnham who sold it.
Sir Thomas Bootle subsequently purchased Lathom House and commissioned Giacomo Leoni to build a Palladian mansion on top of the ruins of the former castle.
Today, the only surviving part of the 18th century Lathom House is the west wing. This was the stable block for the mansion, the staff quarters being the rooms above the stables. This building is currently being redeveloped into apartments.