Question: Which language was spoken by the inhabitants of the British Isles during the era of the colonizers of the country in the 1st century BC where Marwan died?

<P0-S0> At the time of the Roman Empire, about two thousand years ago, various tribes, which spoke Celtic dialects of the Insular Celtic group, were inhabiting the islands. <P0-S1> The Romans expanded their civilisation to control southern Great Britain but were impeded in advancing any further, building Hadrian's Wall to mark the northern frontier of their empire in 122 AD. <P0-S2> At that time, Ireland was populated by a people known as Hiberni, the northern third or so of Great Britain by a people known as Picts and the southern two thirds by Britons. <SEP> <P1-S0> the history of pre-celtic europe and the exact relationship between ethnic, linguistic and cultural factors in the celtic world remains uncertain and controversial. <P1-S1> the exact geographic spread of the ancient celts is disputed; in particular, the ways in which the iron age inhabitants of great britain and ireland should be regarded as celts have become a subject of controversy. <P1-S2> according to one theory, the common root of the celtic languages, the proto - celtic language, arose in the late bronze age urnfield culture of central europe, which flourished from around 1200 bc. <P1-S3> according to a theory proposed in the 19th century, the first people to adopt cultural characteristics regarded as celtic were the people of the iron age hallstatt culture in central europe (c. 800 -- 450 bc), named for the rich grave finds in hallstatt, austria. <P1-S4> thus this area is sometimes called the ``celtic homeland ''. <P1-S5> by or during the later la tène period (c. 450 bc up to the roman conquest), this celtic culture was supposed to have expanded by trans - cultural diffusion or migration to the british isles (insular celts), france and the low countries (gauls), bohemia, poland and much of central europe, the iberian peninsula (celtiberians, celtici, lusitanians and gallaeci) and northern italy (golasecca culture and cisalpine gauls) and, following the celtic settlement of eastern europe beginning in 279 bc, as far east as central anatolia (galatians) in modern - day turkey. <SEP> <P2-S0> Around 746, Abu Muslim assumed leadership of the Hashimiyya in Khurasan. <P2-S1> In 747, he successfully initiated an open revolt against Umayyad rule, which was carried out under the sign of the black flag. <P2-S2> He soon established control of Khurasan, expelling its Umayyad governor, Nasr ibn Sayyar, and dispatched an army westwards. <P2-S3> Kufa fell to the Hashimiyya in 749, the last Umayyad stronghold in Iraq, Wasit, was placed under siege, and in November of the same year Abu al-Abbas was recognized as the new caliph in the mosque at Kufa. <P2-S4> [citation needed] At this point Marwan mobilized his troops from Harran and advanced toward Iraq. <P2-S5> In January 750 the two forces met in the Battle of the Zab, and the Umayyads were defeated. <P2-S6> Damascus fell to the Abbasids in April, and in August, Marwan was killed in Egypt. <SEP> <P3-S0> In 332 BC, Macedonian ruler Alexander the Great conquered Egypt as he toppled the Achaemenids and established the Hellenistic Ptolemaic Kingdom, whose first ruler was one of Alexander's former generals, Ptolemy I Soter. <P3-S1> The Ptolemies had to fight native rebellions and were involved in foreign and civil wars that led to the decline of the kingdom and its final annexation by Rome. <P3-S2> The death of Cleopatra ended the nominal independence of Egypt resulting in Egypt becoming one of the provinces of the Roman Empire. <SEP> <P4-S0> the earliest known references to the islands as a group appeared in the writings of sea-farers from the ancient greek colony of massalia. <P4-S1> the original records have been lost; however, later writings, e.g. <P4-S2> avienus's ora maritima, that quoted from the massaliote periplus (6th century bc) and from pytheas's on the ocean (circa 325–320 bc) have survived. <P4-S3> in the 1st century bc, diodorus siculus has prettanikē nēsos, "the british island", and prettanoi, "the britons". <P4-S4> strabo used βρεττανική (brettanike), and marcian of heraclea, in his periplus maris exteri, used αἱ πρεττανικαί νῆσοι (the prettanic isles) to refer to the islands. <P4-S5> historians today, though not in absolute agreement, largely agree that these greek and latin names were probably drawn from native celtic-language names for the archipelago. <P4-S6> along these lines, the inhabitants of the islands were called the πρεττανοί (priteni or pretani). <P4-S7> the shift from the "p" of pretannia to the "b" of britannia by the romans occurred during the time of julius caesar.