A newly discovered 1,700-year-old church in Ethiopia is shedding fresh light on the spread of Christianity into sub-Saharan Africa.

The remains of the Roman-style basilica are from the fourth century AD and have been uncovered in Beta Samati, a town that was once part of the ancient Aksumite civilisation. 

According to a paper published in Antiquity, the ruins are 60ft by 40ft and date back to the time when Christianity was adopted as the Aksumite Empire's official religion. 

The Smithsonian reports that the church and the findings from the site "confirm Ethiopian tradition that Christianity arrived at an early date in an area nearly 3,000 miles from Rome."

"The find suggests that the new religion spread quickly through long-distance trading networks that linked the Mediterranean via the Red Sea with Africa and South Asia, shedding fresh light on a significant era about which historians know little," it adds.

The researchers said that the church makes them "feel more confident in dating the arrival of Christianity to Ethiopia to the same time frame" as Constantine granted freedom of worship to Christians in the fourth century AD. 

Dr Aaron Butts, a professor of Semitic and Egyptian languages at Catholic University in Washington DC, told The Smithsonian that the find was "to my knowledge the earliest physical evidence for a church in Ethiopia", as well as all of sub-Saharan Africa. 

Lead archaeologist Michael Harrower, of John Hopkins University, revealed that while the Aksumite empire was at one time "one of the world's most influential ancient civilizations", it "remains one of the least widely known."

"The excavations of Beta Samati help fill important gaps in our understanding of ancient Pre-Aksumite and Aksumite civilisations," he said.