The 40s ran from January 1, AD 40, to December 31, AD 49. Following the assassination of Caligula, Claudius became Roman emperor in AD 41. In AD 43 he sent Aulus Plautius with four legions across the Channel, initiating the decades-long Roman conquest of Britain.
Christianity reached Egypt with the founding of the Church of Alexandria, whose first patriarch was Mark the Evangelist. James the Great, one of the Twelve Apostles and according to the New Testament, the first of them to be martyred, was killed in AD 44. Claudius expelled Jews from Rome at some point between AD 41 and 53. Scholars explain the measure to his concern with public order in Rome rather than a policy directed against Judaism.
A famine struck Judea between AD 44 and 48. Josephus records that Helena of Adiabene provided grain and dried figs to the people of Jerusalem, while her son Izates sent money to the city's leaders.
In the absence of reliable demographic data, estimates of the world population in the 1st century vary widely: figures for AD 1 ranging from 150 to 300 million. Demographers rarely attempt to estimate the population for most specific years in antiquity, instead giving approximate numbers for round years such as AD 1 or AD 200. Scott Manning has tentatively put the population in AD 40 at 247 million.[self-published source]
Caligula reforms the principatus into a HellenisticAutocracy. He distributes honors carelessly, declares himself a god and orders that all the heads of the Greek deity statues be replaced by his. He also appoints his horse, Incitatus, to the Senate.
January 25 – The Apostle Paul is converted to Christianity (the exact date is not provided in texts, but the Roman Catholic Church chooses to commemorate this date).
Emperor Claudius returns from his British campaign in triumph, the south-east part of Britannia now held by the Roman Empire, but the war will rage for another decade and a half.
Cauci pirates led by the Roman deserter Gannascus ravage the Gallic coast; Corbulo uses the Rhine fleet against them. The Frisian revolt is suppressed.
Publius Ostorius Scapula, governor of Britain, announces his intention to disarm all Britons south and east of the Trent and Severn. The Iceni, an independent, allied kingdom within that area, revolt but are defeated. Ostorius then moves against the Deceangli in north Wales, but is forced to abandon the campaign to deal with a revolt among the allied Brigantes.
Gallic nobles are admitted to the Roman Senate. Claudius grants the rights of citizenship to the Aedui.
Emperor Guang Wu of Han, restores Chinese domination of Inner Mongolia. The Xiongnu are made confederates and guard the Northern border of the empire.
↑Haub (1995): "By 1 A.D., the world may have held about 300 million people. One estimate of the population of the Roman Empire, from Spain to Asia Minor, in 14 A.D. is 45 million. However, other historians set the figure twice as high, suggesting how imprecise population estimates of early historical periods can be."
↑Fabre, Guilhem; Fiches, Jean-Luc; Paillet, Jean-Louis (1991). "Interdisciplinary Research on the Aqueduct of Nimes and the Pont du Gard". Journal of Roman Archaeology. 4: 63–88. doi:10.1017/S104775940001549X.
↑Wadley, Stephen (2006). Proceedings of the First North American Conference on Manchu Studies. Portland, Oregon: Otto Harrassowitz Verlag. p.133. ISBN978-3-447-05226-9.