Little is know about the travels of the apostles after Jesus' ascension into Heaven, but local tradition claims that St. Andrew the Apostle traveled to Ukraine and erected a cross near Kyiv.
The 1917 book, The Conversion of Europe, gives a brief summary of this tradition.
There is little evidence that supports this story, but it is believed that the Cathedral of St. Andrew in Kyiv was built on the site of St. Andrew's cross.
St. Andrew has been a patron saint of both Ukraine and Russia for many centuries, and the church built there is regarded as an essential part of the history of Christianity in that region of the world.
In the Western Church, other traditions point to Andrew as the Apostle to the Greeks. It is believed that he preached to Greek communities and was martyred at Patras on a cross in the shape of an X. His relics were eventually transferred to the Duomo Cathedral in Amalfi, Italy.