Beotibar is a locality near Tolosa in the Gipuzkoa province of northern Spain, in the northeastern part of the autonomous community of the Basque Country.
Beotibar is renowned in Basque history as the site of the battle on 19 September 1321 in which Guipuzcoans defeated the Navarrese.
Essentially, the battle was the result of the very complicated geopolitical forces at work in the Middle Ages that went into shaping what one day would become Spain.
This lasted until Guipuzcoa, Alava, and Vizcaya broke away from that kingdom amid a difficult political situation and became integrated into Castile under a treaty in 1200.
There exists a description of the battle of Beotibar by Juan Zaldibia in his book Suma de las cosas cantábricas y guipuzcoana as well as an old Basque song that recalls the victory.