It is passé simple. 

Noting that this lesson is at B2, it is probably reasonable to expect to come across some examples using this tense, as it is still found in formal writing, and old texts. 

Worth learning to recognise for reading and understanding French ‘formal’ writing, although barely at all for modern speech -  a few exceptions in expressions aside. 

https://www.wordreference.com/conj/frverbs.aspx?v=se%20marier

Le Passé Simple (Indicatif)