The Valide Sultan influenced the way that the Ottoman sultans waged wars of conquest. The Ottoman conquests were mostly in the West until the mid-1500s, however, the ethnic background of the Valide Sultan was an independent and major determinant of whether these conquests would be for North Africa or the Middle East, or in Europe. The sultans were more likely to be mindful of their matrilineal descent. The rule of a sultan with a European maternal ethnic background was sufficient to counteract more than 70 per cent of the empire's western orientation in imperial conquests. In contrast, the sultans with European matrilineal descent had no discernable influence on the empire's eastern conflicts whereas the Ottomans' military ventures in Europe were generally reinforced by a Muslim matrilineal genealogy. Regardless of how the Ottoman harem had developed over time as an organization, the main observation is that the mothers of the princes were solely responsible for their upbringing. And the royal mothers had the most direct and sustained interaction with the future sultans of the Ottoman Empire.