Fernando António Nogueira Pessoa was a Portuguese poet, writer, literary critic, translator, publisher, and philosopher, described as one of the most significant literary figures of the 20th century and one of the greatest poets in the Portuguese language. He also wrote in and translated from English and French.

Alberto Caeiro is a heteronym which the Portuguese poet Fernando Pessoa began to use in 1914 and introduced in print in 1925. In his fictional biography, Caeiro was born in Lisbon on 16 April 1889, lived most his life in a village in Ribatejo and died in 1915. He was the leader and teacher of a group of neopagan poets and intellectuals that included Pessoa's other heteronyms António Mora, Ricardo Reis and Álvaro de Campos.