[1][better source needed] The first known reference to Avelar is from the year 1137, when Afonso Henriques (not yet King of Portugal) cites an "Avellaal" on the foral granted to Penela.

Those confiscated goods were later passed on to the House of the Infantado, created by King John IV himself as an appanage for the second eldest son of the Portuguese monarch.

[1][4] On December 31, 1836, due to a royal decree, Avelar loses its title of vila and becomes part of the concelho of Chão de Couce [pt] until 1855.

[12] Instead, the celebration was shortened to a single, brief "Day of Vila of Avelar" public meeting on June 21, taking necessary precautions to prevent further spread of the virus.

[4][25][26] As of February 2020, president of Avelar's legislature (Assembleia de Freguesia) is Dina Maria Caseiro Henriques Rosa, of the Social Democratic Party.