The ancient city of Ostrakinē, situated c. 98km east of Pelusium, is associated with the modern-day town of al-Filusiyya. Much of the ancient ruins are today submerged in the salt marshes of the Bardawīl Reef, with the remaining features located on four ‘islands’ – a large ‘main’ island, with three smaller islands situated to the north-east (Clédat 1910: 220, 222). The earliest attestation of the site is from the 1^st century BCE, with the latest in the 7^th century CE (Verreth 2006: 351, 353). Clédat considered that the city fell under the Arabs, while Grossmann supposed that it was destroyed by the Persians, but neither hypothesis can be confirmed based on the available sources (Grossmann 1991: 1414; Clédat 1916: 7, 10, 13). There were some figures who contested the correlation between ancient Ostrakinē and modern al-Filusiyya in the early 20^th century, such as J. Maspero, but the relationship is today considered definite (Verreth 2006: 354, 395). A key portion of confirming evidence, which remains unexamined, are some 50 Greek ostraca found in a collapsed wall immediately south-west of the south basilica (A-151), all written by the same person, often mentioning the place name Ostrakinē. Taken to Cairo, these ostraca remain unedited (Clédat 1916: 27; Verreth 2006: 391).

The textual sources make no mention of Christian monuments in the city, but there was undoubtedly a Christian community present in the fourth century given that the Arian bishop of Ostrakinē Theoktistos is mentioned having attended the synod of Seleukeia in 359 (Verreth 2006: 372). A total of three bishops are known from the mid-fourth to the mid-fifth century (Verreth 2006: 352). Despite their exclusion from known literary works, there are four Christian structures documented at the site: the north (A-?) and south basilicas (A-151, also known as the ‘large south church’), and a ‘fortified monastery’ (A-150/A), all excavated by Clédat, as well as an additional church found in the 70s, c. 70m north of the south basilica (A-152/A), described by Grossmann as being situated on an island… (Verreth 2006: 392; Grossmann 2002: 480). The fort structure, which was only partially excavated (Clédat 1916: figs. 2 and 3) was considered by Clédat to have been one of the joint monastery-fort buildings constructed in the Sinai by Justinian, and, while the presence of Christian occupants is unquestionable (Clédat 1916: 15-20 and figs. 5, 7, 9, 11), the idea that it was inhabited exclusively by monks has been rejected (Clédat 1916: 11, 15; Verreth 2006: 391 n. 1594). It is known that, in the second century, and likely also in the third, Roman soldiers were stationed at Ostrakinē, but additional information is wanting (Verreth 2006: 352). The large south church and the nearby church (A-151 and A-152/A respectively) were to the immediate north of the monastery (A-150/A), while further north was situated an industrial quarter (A-150/B) and the agora (A-153 = Taba Felusiyat) (Verreth 2006: 393). Some 2km north of the monastery was an area Clédat considered the harbour, though there is no definitive evidence supporting the notion that Ostrakinē was a harbour town (Verreth 2006: 352). This area is where the north basilica (A-?) is located (Clédat 1916a, p. 8; Verreth 2006: 390). Both the south basilica and the church identified by the Israelis were said to contain numerous burials, while the latter additionally included a reliquary (Grossmann 2002: 481; Verreth 2006: 391).

Securely placing any of the occupation phases of these structures in the fourth century is difficult. The first of the two identified phases of the ‘fortified monastery’ is the 4^th-5^th century (Clédat 1916: 13-20; Kool, p. 3), while the three churches are all understood to date from the 5^th century onwards, with the northern basilica presumed by Clédat to be the oldest (Kool, p. 2, 6-7; Clédat 1916: 27; Grossmann 2002: 477). Numismatic evidence potentially supports an earlier fourth century phase for the church found by the Israeli mission (A-152/A), but this hypothesis is somewhat unsubstantiated given the reality that the 4^th century nummi are known to have remained in circulation well into the fifth century and even later (Kool, p. 6-7; Verreth 2006: 392). An additional monastery is mentioned by Oren, not far from the ‘small’ (i.e. northern?) basilica, but it was never excavated (Oren and Figueras 1982: 38; Verreth 2006: 391).

The Christian occupation of the site is further supported by numerous explicitly Christian stelae existent in various museum collections, all of which are understood to come from the nearby cemetery of ‘el-Khuinat’ (2km), considered by Oren to have been one of the burial grounds of ancient Ostrakinē (Oren and Figueras 1982: 45; Oren 1993a: 1173; Dahari and Di Segni 2013). This presumed provenance is based on specific characteristics shared with stelae definitively originating from that cemetery – formulaic features of the text, decorative elements (the upper part being roughly in the shape of a human head with engraved facial features), and type of stone from which they are carved (kurkar) (Verret 2006: 399). These are roughly dated to the late fourth-fifth century (Dahari and Di Segni 2013, p. 127 and 136). See artefacts.