More than 300 leather-clad motorcyclists, led by Father Ewald Meixner, parked their machines at the steps of the cathedral before the first such bike blessing in Scotland was performed.
The group, which is taking part in “Holytour 2014”, had contacted officials at the cathedral to ask for the blessing which was conducted by Fr Meixner and the Rev Bill Armitage from St Giles’.
Previous ceremonies have been conducted for the bikers at the Vatican in Rome and Notre Dame in Paris.
The tour involves annual trips to holy sites. It also targets stretches of open road with challenging driving conditions.
The eight-day tour of Scotland has included Skye and the Highlands, as well as a visit to Rosslyn Chapel in Midlothian – long-rumoured to be a possible site of the Holy Grail.
Fr Meixner, a life-long motorcycle enthusiast, said: “We always say we are blessing the bikes, but in reality we are blessing the people driving the bikes. This is especially so because this is a very dangerous form of transport on the road.”
Fr Meixner and the Rev Armitage walked among the bikes saying prayers and speaking to the bikers before the group entered the cathedral for a short service conducted in German and English.
The bikers, who were carrying their motorcycle helmets, draped their leather jackets over the back of the chairs while banners and insignia were placed over the altar.
During the service Fr Meixner said that on the road as in life, “there is always risk, we don’t know what to expect. But while we are all on a constant journey to find the Holy Grail, all of us leave something of ourselves behind for other people when we travel”.
The group then stood in a circle holding hands round the altar for a hymn and more prayers.
Mr Armitage said this was the first time he had been asked to take part in such an occasion.
He told The Scotsman: “I have blessed caravans, houses and boats before, but never something like this. I’ve been very impressed with how things have gone. The group wrote to us and asked if we’d do this for them and it took me less than a second to agree to do it. I’ll try anything – the church should be open to everything and not turn people away.”
During the blessing, the Rev Armitage said: “Sisters and brothers, go in peace. Travel safely.”
One of the bikers, Mario Dax, 38, a civil engineer from Gratz, in Austria, said: “The blessing was quite cool. This has been really good. We came through heavy rain in the town and were really pleased to reach somewhere where we could sit inside.
“We have been together as a group for about six or seven years and we are more like a family than a motorbike chapter.”
The group’s Motorrad und Urlaub (Motorcycles and Holidays) website says a “motorcycle tour of Scotland is an incredible experience. Narrow winding roads, driving on the left, and especially the weather – no reason to be bored.”
The site describes Scots as being from “an adventurer society” who “take the weather as it is, do not complain about the rain and always have a smile on their lips”.
Jane Roy, an independent tourist guide with travel site Eyes on Scotland, who advised the group on destinations, said: “It has been a pleasure meeting the group and attending the blessing. I’ve found it quite surprising to find that about a third of them were women.”
St Giles’ Cathedral has been one of Edinburgh’s religious centres for 900 years.