The Liberal government of the United Kingdom of Great Britain and Ireland that began in 1859 and ended in 1866 consisted of two ministries: the Second Palmerston Ministry and the Second Russell Ministry.
After the fall of the second of Lord Derby's short-lived attempts at governments in 1859, the Viscount Palmerston returned to power, this time in alliance with his former rival the Earl Russell, in what is regarded as the first Liberal government. Palmerston remained as Prime Minister until his death in 1865, when Russell succeeded him. However, disunity within the party caused the fall of the government in the following year, and Lord Derby formed another Conservative ministry.