 Complete the following phrase:  At independence, a few princely dignities were accorded the Imperial familys relations and three titles of nobility  the latter already under application with the Spanish government  were recognized by the Congress of the First Mexican Empire, such as the Marqués de Samaniego del Castillo. Knighthoods were also created, most notably, of Guadalupe. Throughout the 19th century others received pontifical titles of nobility, and through loopholes in Spanish law, had these titles recognized as títulos de Castilla; these are known as títulos negros and include the titles of the marqués de Barrón, conde de Subervielle, conde del Valle Fernández del Valle family, duquesa de Mier, and others. Many of these families were part of the hidalgo class. Some families, after 