The night had grown late and I was tired, so I stayed at an inn.
Literal
Night [subj-が] deepened-[and-て] was-tired-[because-ので], I [topic-は] inn [at-に] stayed-overnight.
宿 is the shorter, slightly more modern word for inn or lodging. The te-form 更けて chains the night-deepening into 疲れていた ('was tired'), and ~ので supplies the reason for staying overnight.