My thesis examines Ottoman imperial women’s contribution to the Tanzimat era (1839-1876), a period characterized by various attempts to reform the Ottoman Empire and curtail the nationalist movements of ethnic groups within its territory. I focus on two queen mothers who lived during this period; Bezmialem Sultan (1798?-1853) and Pertevniyal Sultan (1810?-1884). They were the last two queen mothers of the Ottoman Empire and the wives of Sultan Mahmud II (r. 1808-1839), the so-called architect of the Tanzimat period. Scholars rarely mentioned them in regard to the Tanzimat. In my analysis the queen mothers’ vakfiyes played a key role since they constituted the most important written documents explaining their intentions, as well as the minute details of their projects. Comparing their charitable foundations’ deeds has shown that in their prayer sections and original vakfiyes both valide sultans employed not only the same format, but also exactly the same wording. In this respect, my analysis of these sources broadens our understanding of vakfiyes, since many scholars have claimed to find the patrons’ active voices in these sections per se. Besides the vakfiyes, I focused on many untapped archival sources, memoirs, travelers’ accounts, contemporary chroniclers, their own writings, as well as artworks dedicated to them. These archival sources have disclosed how¬?through their mosques, schools and hospitals?both queen mothers endorsed various pioneering projects. A closer examination of these projects reveals that they followed slightly differing patterns of patronage, sometimes also different from their sons’ patronage, even though they first and foremost had to support the legitimacy of their sons’ rules. These two queen mothers subtly guided not only their commissions’ construction, but also how individuals should experience these buildings. They mixed traditional concepts with new patterns in both architecture and function. The Tanzimat era can be better understood by analyzing the involvement and patronage of its queen mothers and evaluating diverse layers of power; the harem as an alternative site of power should not be disregarded. In this sense, my thesis contributes to the rich academic works concentrating on women’s patronage in the fifteenth to eighteenth centuries.