In just a couple of weeks, Celtic will start their European campaign against FC Stjarnan of Iceland, and they will be extremely wary of the threat a tie like this could pose. The Icelandic side are most famous for their inventive celebrations, which Celtic fans will be praying they won't see any time soon. Celtic and Rangers have had some incredible European nights over the years. Rangers claimed European glory in 1972 with the Cup Winner's Cup, and have beaten the likes of Bayern Munich and Juventus, among other great names. Celtic won the European Cup in 1967 with a stunning victory over Inter Milan, and just three years ago upset the mighty Barcelona. The two clubs have found their niche as underdogs on the biggest stage, but have often struggled as overwhelming favourites in ties they should easily win. With one hundred league titles between the two Glasgow clubs, the sides have had ample European experience between them and can be considered as reasonable forces on the continent. However, for every Bayern, there was a Kaunas and for every Barcelona there was a Bratislava. The Old Firm have fallen to some extraordinary defeats in European competition. Some of the entries on this list are absolutely massive scores, some are against absolutely rubbish teams, but they are all extremely embarrassing.