British P.M. before Gladstone Crossword Clue

 The British Prime Minister before William Ewart Gladstone was Henry John Temple, 3rd Viscount Palmerston. He served as Prime Minister from 1855 to 1865 and again from 1868 to 1872. Palmerston was a Liberal politician and a strong supporter of free trade and British imperialism. He is also known for his witty and outspoken personality.

Gladstone was a Liberal politician who served as Prime Minister four times, from 1868 to 1874, 1880 to 1885, 1886, and 1892 to 1894. He was a leading figure in the movement for social reform and opposed the expansion of the British Empire.

So, the answer to the crossword clue "British P.M. before Gladstone" is Palmerston.