Livy's description of a great fire which broke out about the forum B.C. 211 affords some topographical particulars: "Interrupit hos sermones nocte, quae pridie Quinquatrus fuit, pluribus simul locis circa forum incendium ortum. Eodem tempore septem Tabernae, quae postea quinque, et argentariae, quae nunc Novae appellantur, arsere. Comprehensa postea privata aedificia, neque enim tum basilicae erant: comprehensae Lautumiae, forumque piscatorium, et atrium regium. Aedis Vestae vix defensa est" (xxvi. 27). As the fire, wilfully occasioned,broke out in several places, and as the Curia Hostilia does not seem to have been endangered, we may perhaps conclude that the Septem Tabernae here mentioned were on the S. side of the forum. The argentariae afterwards called Novae were undoubtedly on the N. side, and, for the reason just given, they perhaps lay to the E. of the curia, as the fire seems to have spread to the eastward... The Basilica Porcia must have stood close to the curia, since it was destroyed by the same fire which consumed the latter, when the body of Clodius was burnt in it (Ascon. ad Cic. pro Mil. Arg. p. 34, Orell.); but it must have been on the eastern side, as objects already described filled the space between the curia and the Capitoline hill...

...Sulla when dictator seems to have made some changes in the curia (Plin. xxxiv. 12), and in B.C. 51, after its destruction in the Clodian riots, it was rebuilt by his son Faustus. (Dion. cass. xl. 50) Caesar, however, caused it to be pulled down in B.C. 45, under pretence of having vowed a temple to Felicitas, but in reality to efface the name of Sulla. (Id. xliv. 5.)...

One of the most important of these designs of Caesar’s was the building of a new curia or senate-house, which was to bear his name. Such a building would be the badge of the senate's servitude and the symbol of his own despotic power. The former senate-house had been erected by one of the kings; the new one would be the gift of the first of the emperors. We have mentioned the destruction of the old curia by fire in the time of Sulla, and the rebuilding of it by his son Faustus; which structure Caesar caused to be pulled down under a pretence, never executed, of erecting on its site a temple of Felicitas.

The curia founded by Pompey near his theatre in the Campus Martius- the building in which Caesar was assassinated- seems to have been that commonly in use; and Ovid (Met. xv. 801), in describing that event, calls it simply Curia: -

We may suppose that when Caesar attained to supreme power he was not well pleased to see the meetings of the senate held in a building dedicated by his great rival.

A new curia was voted a little before Caesar's death, but he did not live to found it; and the Monumentum Ancyranum shows that it was both begun and completed by Octavianus.

Respecting the site of the CURIA JULIA the most discordant opinions have prevailed. Yet if we accept the information of two writers who could not have been mistaken on such a subject, its position is not difficult to find. We learn from Pliny that it was erected on the comitium: "Idem (Augustus) in Curia quoque quam in Comitio consecrabat, duas tabulas impressit parieti" (xxxv. 10); and this site is confirmed by Dion Cassius (xlvii. 19). It is impossible to find any other spot for it on the comitium than that where the old curia stood. Besides the author last quoted (Dion Cassius) expressly informs us that in consequence of some prodigies that occurred in the year before Caesar's murder it had been resolved to rebuild the Curia Hostilia (Ib. xlv. 17.) At the time when this decree was made Caesar was himself pontifex maximus; it would have been a flagrant breach of religion to neglect a solemn vow of this description; and we cannot therefore accept Becker's assertion that this vow was never accomplished. (Handb. p. 331, note 608.) We cannot doubt that the curia erected by Augustus was in pursuance of this decree, for Caesar did not live even to begin it ("Curiam et continens ei Chalcidicum- feci," Mon. Ancyr); but though the senate-house was rebuilt, it was no longer named Hostilia, but, after its new founder, Julia. Now what has Becker got to oppose to all this weight of testimony? Solely a passage in Gellius- which, however, he misapprehends, - in which it is said, on the authority of Varro, that the new curia had to be inaugurated, which would not have been the case had it stood on the ancient spot ("Tum adscripsit (Varro) de locis in quibus senatus consultum fieri jure posset, docuitque confirmavitque, nisi in loco per augures constito, quod templum appellaretur, senatusconsultum factum esset, justum id non fuisse. Propterea et in Curia Hostilia et in Pompeia, et post in Julia, cum profana ea loca fuissent, temple esse per augures constituta," xiv. 7.7) But Becker has here taken only a half view of these augural rites. As a temple could not be built without being first inaugurated, so neither could it be pulled down without being first exauguarated. This is evident from the accounts of the exauguration of the fanes in order to make room for the temple of the Capitoline Jupiter. ("Et, ut libera a caeteris religionibus area esset tota Jovis templique ejus, quod inaedificaretur, exaugurare fana sacellaque statuit, quae aliquot ibi a tatio rege, consecreta inaugurataque poste fuerant," Liv. i. 55, cf. v. 54; Dion. Halic. iii. 69.) When Caesar, therefore, pulled down the curia of Faustus he first had it exaugurated, by which the site again became a locus profanus, and would of course require a fresh inauguration when a new temple was erected upon it. The curia in use in the time of Propertius (iv. 1.11) must have been the Curia Julia; and the following lines seem to show that it had risen on the site of the ancient one: -

A further confirmation that the new curia stood on the ancient spot is found in the fact that down to the latest period of the Empire that spot continued to be the site of the senate-house. The last time that mention is made of the Curia Julia is in the reign of Caligula ("Consensit (senatus) ut consules non in Curia, quia Julia vocabatur, sed in Capitolium convocarent," Suet. Cal. 60); and as we know that the curia was rebuilt by Domitian, the Julia must have been burnt down either in the fire of Nero, or more probably in that which occurred under Titus. It is not likely, as Becker supposes (Handb. p. 347), that Vespasian and Titus would have suffered an old and important building like the curia to lie in ashes whilst they were erecting their new amphitheatre and baths. The new structure of Domitian, called Senatus in the later Latin ("Senatum dici et pro loco et pro hominibus," Gell. xviii. 7, 5), is mentioned by several authorities (Hieronym. an. 92. i. p. 443, ed. Ronc.; Cassiod. Chron. ii. p. 197; Catal. Imp. Vienn. p. 243.) The place of this senatus is ascertained from its being close to the little temple of Janus Geminus, the index belli pacisque Procop. B.G. i. 24); and hence from its proximity to Numa's sacellum it was sometimes called "Curia Pompiliana" (Vopisc. Aurel. 41, Tacit. 3.) The same situation is confirmed by other writers. Thus Dion Cassius mentions that Didius Julianus, when he first entered the curia as emperor, sacrificed to the Janus which stood before the doors (lxxiii. 13). In the same manner we find it mentioned in the Notitia in the viiith Region. That it occupied the site of the ancient church of S. Martina, subsequently dedicated to and now known as S. Luca, close to the arch of Severus, appears from an inscription (Gruter, clxx. 5) which formerly existed in the Ambo, or hemicycle, of S. Martina, showing that this hemicycle, which was afterwards built into the church, originally formed the Secretarium Senatus (Urlichs, Rom. Top. p. 37, seq.; Preller, Regionem, p. 142.) The Janus temple seems to have been known in the middle ages under the appellation of templum fatale, by which it is mentioned in the Mirabilia Urbis. ("Juxta eum templum fatale in S. Martina, juxta quod est templum refugii, i.e., S. Adrianus," Ib.) In the same neighbourhood was a place called in the later ages "Ad Palmam," which also connects the senatus with this spot, as being both near to that place and to the Arcus Severi. Thus Ammianus: "Deinde ingressus urbem Theodoricus, venit ad Senatum, et ad Palmam populo alloquutus," & c. (Excerpt. de Odo. 66.) And in the Acta SS., Mai. vii. p. 12: "Ligaverunt ei manus a tergo et decollaverunt extra Capitolium et extrahentes jactaverunt eum juxta arcum triumphi ad Palmam." (cf. Anastas. V. Sist. c. 45.) The appellation "ad Palmam" was derived from a statue of Cluaudius II. clothed in the tunica palmata, which stood here: "Illi totius orbis judicio in Rostris posita est columna cum palmata statua superfixa." (Treb. Pollio, Claud. c. 2.)

We cannot doubt, therefore, that the curia or senatus built by Domitian was near the arch of Severus; which is indeed admitted by Becker himself (Handb. p. 355). But, from his having taken a wrong view of the situation of the comitium, he is compelled to maintain that this was altogether a new site for it; and hence his curia undergoes no fewer than three changes of situation, receiving a new one almost every time that it was rebuilt, namely, first, on the N. side of his comitium, secondly on the S. side, and thirdly near the Arcus Severi, for which last site the evidence is too overwhelming to be rejected. We trust that our view is more consistent, in which the senate-house, as was most probable, appears to have always retained its original position. And this result we take to be no slight confirmation of the correctness of the site which we have assigned to the comitium. In their multitudinous variations, Bunsen and Becker are sore puzzled to find a place for their second curia- the Julia- on their comitium, to which the passages before cited from Pliny and Dion inevitably fix them. Bunzen's strange notions have been sufficiently refuted by Becker (Handb. p. 333), and we need not therefore examine them here. But though Becker has succeeded in overthrowing the hypothesis of his predecessor, he has not been able to establish one of his own in its place. In fact he gives it up. Thus he says (p. 335) that, in the absence of all adequate authority, he will not venture to fix the site of the curia; yet he thinks it probable that it may have stood where the three columns are; or if t hat will not answer, then it must be placed on the (his) Vulcanal. But his complaint of the want of authorities is unfounded. If he had correctly interpreted them, and placed the comitium in its right situation, and if he had given due credit to an author like Dion Cassius when he says (l.c.) that it was determined to rebuilt the Curia Hostilia, he had not needed to go about seeking for impossible places on which to put his Curia Julia.

Thomas Henry Dyer, Ancient Rome (London: John Murray, Albemarle St., 1864), 71-73.