In 1636, George, Duke of Brunswick-Lüneburg, began converting the monastery into a rather small late-renaissance palace as his residence as ruler of the Principality of Calenberg.
His son, Elector Ernest Augustus, had it enlarged and modernized and added a theatre in the late 17th century.
The youngest son of George III, Prince Adolphus, Duke of Cambridge, officiated as Viceroy of Hanover from 1816.
Kings Ernest Augustus and George V were the first and only monarchs to have their main residence in the state capital and in the Leine Palace between 1837 and 1866.
During World War II, the Leine Palace burnt out completely after Allied aerial raids.