Complex sentence: Iorek Byrnison defeats Iofur towards the end of the first book and returns the bears to their traditions; later in the series, however, he begins to feel human feelings such as doubt, especially in connection to the Subtle Knife.
Split into simpler sentences: Iorek Byrnison defeats Iofur towards the end of the first book and returns the bears to their traditions. Later in the series, however, he begins to feel human feelings such as doubt, especially in connection to the Subtle Knife.