David A. Myers 
Queens of Old Spain [PDF ebook] 

In Spain, the share of ladies in deciding the political destinies of the country from the throne has been more conspicuous than in other European monarchies. The oriental traditions dominant in Spain for centuries tended to make wives the humble satellites rather than the equal companions of their husbands. But whilst these traditions limited the power of Spanish women generally, they were insufficient to counteract the extraordinary political influence of a series of remarkable feminine personalities who have on occasion during the course of four centuries practically wielded the sceptres of Spain.