<p>This library, located SE of the Palatine Temple of *Apollo, had both Greek and Latin collections (Suet., <i>Aug</i>. 29.3; <i>CIL</i> VI 5188-89=<i>ILS</i> 1588-89, 5190-91). It may have been dedicated in 28 B.C. together with the Temple of Apollo (Dio Cass. 53.1.3), although it was not mentioned along with the Portico of the Danaids (s.v. *Porticus: Apollo [Palatium]) and Temple of Apollo in the second book of Propertius (2.31) published in or before 24 B.C.: Thompson). Thompson (339) argues that the library opened after 28 B.C., and was in use probably by 23 B.C. The library was a versatile space, and in addition to storing a dual-language manuscript collection it served as the locale for a number of Senate meetings during Augustus’ reign, especially during his old age (Suet., <i>Aug</i>. 29.3; Palombi); a passage in Suetonius suggests that the Senate met either inside the library or within the library’s portico (<i>loc. cit</i>.).</p> <p>There has been considerable scholarly debate over the form of the Augustan library, which may have consisted of two distinct structures or of one large hall divided into Latin and Greek sections. Ancient sources refer to the library in both the singular (<i>bibliotheca latina graecaque</i>: Suet., <i>Aug</i>. 29.3) and plural (<i>Palatinae bibliothecae</i>: Suet., <i>Gram</i>. 20; τάς τε ἀποθήκας τῶν βιβλίων: Dio Cass. 53.1.3), which leaves both configurations as possibilities (contra, Thompson 338, who argues against twin rooms based upon the singular <i>‘bibliotheca’</i>; Corbier 899 rightly remains unswayed by the linguistic evidence). The Severan Marble Plan (frag. 20b) depicts the library as two adjacent apsidal halls with interior colonnades opening toward the NW (Gros 55); this plan, however, represents the Domitianic library, which may not have preserved its Augustan organization (Corbier 900; contra, Strocka 308 n.27, who argues that the Domitianic library essentially followed the Augustan plan). On the other hand, it can reasonably be assumed from a papyrus describing the reception of the Alexandrian ambassador by Augustus in A.D. 12/13 at the Latin library (<i>P Oxy</i>. 2435 <i>verso</i>: [[ἐν τη Ρ]ωμαικη βυβλιοθηκηι, sic; Lobel and Turner 108) that the Latin and Greek texts were housed in two separate spaces of the Augustan-era library, with the Latin hall also serving for Senate meetings and other official occasions (Corbier 899).</p>