The trouble with omens is that it could depend, in many cases, on point of view. In 1066, the “omens” were indeed rather good if you were a Norman! As for the Star of Bethlehem, I’m not so sure, it’s twelve years out, which is stretching things a bit, moreover, comets were anciently seen as being unlucky or bad omens, so is it likely that this was included in the New Testament narrative? There were a number of other astronomical phenomena at that time that may also have been behind the idea of the star, including one interesting theory involving Jupiter, Venus and Regulus.
One interesting thing about the Titanic, is that the White Star Line – in accordance with its policies anyway – had no traditional naming ceremony, “christening”, nor the traditional bottle of champagne broken across the bows when the ship was launched …
Black cats are an interesting one, it seems that in many parts of the world – including most of Europe – they have been considered unlucky, yet in Britain they’re generally considered as being the opposite, and it’s very good luck if one crosses your path.
Finally, Boudicca’s reading of the omens, with a hare and imploration to Andraste, to guide her to victory, well, err … obviously didn’t work out quite how the Britons had probably hoped.