The Emperor of Portugallia (Swedish: Kejsarn av Portugallien) is a novel by Nobel-laureate Selma Lagerlöf, published in 1914 with drawings by Albert Engström.

He loves his daughter more than anything else, but after she moves to Stockholm at age 18, she stops sending letters home.

The father sinks into a dream world where he imagines she has become a noble empress of "Portugallia", and he thus also a great Emperor himself.

In his role as Emperor residing in the poor countryside, he can challenge the area's social hierarchies: wearing his imperial regalia, he sits at the front of the church, takes place at the head table at parties and tries to socialize with local landlords.The mental breakdown comes from Jan finding out his daughter in Stockholm is really a prostitute and he drifts into being a sort of "holy fool" in the village.

The novel was adapted to silent film by MGM in 1925 as The Tower of Lies, directed by Victor Sjöström and starring Norma Shearer and Lon Chaney.