What's not Traditional About Same Sex Weddings?

When Christians rant on about "traditional marriage", the tradition to which they refer isn't all that old (if you exclude the fact that some of them believe the Universe is only 10 thousand years old!). But when they imply that same sex unions are a 21st century phenomenon, they're on very dodgy ground.

Here's the science part:

Prof. John Boswell, the late Chairman of Yale University’s history department, discovered that in addition to heterosexual marriage ceremonies in ancient Christian church liturgical documents, there were also ceremonies called the
“Office of Same-Sex Union” (10th and 11th century), and the “Order for Uniting Two Men” (11th and 12th century). These church rites had all the symbols of a heterosexual marriage: the whole community gathered in a church, a blessing of the couple before the altar was conducted with their right hands joined, holy vows were exchanged, a priest officiatied in the taking of the Eucharist and a wedding feast for the guests was celebrated afterwards. These elements all appear in contemporary illustrations of the holy union of the Byzantine Warrior-Emperor, Basil the First (867-886 CE)and his companion John. Such same gender Christian sanctified unions also
took place in Ireland in the late 12thand/ early 13th century, as the chronicler Gerald of Wales (‘Geraldus Cambrensis’) recorded.

Sounds like gay marriage is pretty traditional to me.