Born at Tabuaço, near Viseu in central Portugal, Bothelho was educated in the Military College, Polytechnic School and Army School in Lisbon, going on to make a successful career as an army officer, reaching the rank of colonel, then Parliamentary deputy, senator, and finally Portuguese ambassador to the Argentine Republic, dying in post in Buenos Aires.

He took an active interest in art as a critic, participated in various artistic groups and official bodies and received a number of official honours. At the same time he was active as an author, publishing a range of poetry, plays, short stories and novels. The most famous of his novels is titled O Barão de Lavos (The Baron of Lavos, 1891) which is one of the earliest major full-lenght novels published in any European language to have a male homosexual as it central, overt theme.

Without being pornographic, the novel is quite explicit about the physical relations between The baron and Eugénio, a 16 year-old street urchin the baron seduces. The novel offers some interesting glimpses of gay life in Lisbon of the period. This novel was translated into Spanish in 1907, but has not been translated since.