Basauri became independent from Arrigorriaga in 1510 or at least , is the date taken as official .
There is no document to verify that at that date any meetings were held between mayors of both towns .
Basauri became independent from Arrigorriaga in 1510 or at least , is the date taken as official , because there is no document to verify that at that date any meetings were held between mayors of both towns .