History of the Vikings

Known Raids
 793 Lindesfarne
 There are many web sites showing the raid there, quite a few movies made too. No lodestone available for quite a few years to come though. Dead reackoning or pure chance, not sure even if they were using the raven technique, that is possible
 More than one reason they chose the monasteries were chosen for the raids I think. The main reason might have been for religious reasons, the other is because they were like the banks in their tim, Not only did they have most of the silver and gold, they had most of the harvests stock, and many other usful items.
794 Wearmouth, Jarrow, and Bede's old monastery (England)
795 Iona (Scotland) and Rathlin Island (Just off Ireland)
799 Aquitane, many, on different island (France)
802 Iona (Scotland)
806 Iona (Scotland)
834 Dorstad (Frisia, That is Holland today I think)
 "Everything destroyed. They slaughtered some, some they away others, and burned the surrounding area" (Annals of St. Bertin's). This was raided many times until the Rhine changed course and it was flooded
835 Isle of Sheppy (England) 
       Noirmoutier, abandoned, now a Viking base (France)
836 Antwerp 
840, Louis the Pious dies, and France is now splintered and localised, there is many feuds and much treachery. 
841 Rouen (France)
842 Quentovic (France)
845 Now ENTERS RAGNAR! although, his force was only 120 ships, compared to King HORIKs 700. 

871 Cambridge (England) Most of the new army are hit by a storm, many find them selves stranded in Wales (there is a slight possability that Ragnar is still alive, but if so,, he would have been reaching the 100 age mark. More likely, some one looking or uhaving the first name Ragnar gets taken if the story is to be believed when it comes to the snake pit at least. Magnus says they just thought  or had heard that Ragnar had been killed and the brothers are mitaken when the put AElla to death)  

Listed Battles
937 Battle of Brunanburh 

Source: Vikings by BBC host of Mastermind, Magnus Magnusson. (p = page number in that book)
External links & compilation  S. Broberg (I do my best to get the correct for you, but no guaranteees)

What the Sagas say:

Online research and links

 Can't say I know for sure, but this is a list from the book, I'll see if they had dates, Can't say that Ragnar was involved in many if any, he's not listed, it is possible thogh. He did exist, and he  was Pagan, didn't want to end up like the poor old French pagans who met Charliemagnes folk.