The Liberal Union, simply and collectively called Liberals, was a political alliance formed in the first years of the 20th century by the Italian Prime Minister and leader of the Historical Left Giovanni Giolitti. The alliance was formed when the Left and the Right merged in a single centrist and liberal coalition which largely dominated the Italian Parliament.

The Left group, later called Historical Left by historians to distinguish it from the left-wing groups of the 20th century, was a liberal and reformist parliamentary group in Italy during the second half of the 19th century. The members of the Left were also known as Democrats or Ministerials. The Left was the dominant political group in the Kingdom of Italy from the 1870s until its dissolution in the early 1910s.