Complex sentence: The Grand Mosque of Copenhagen, official known as Hamad Bin Khalifa Civilisation Center, is a mosque built in 2014 which is the first purpose-built non-Ahmadiyya mosque in Denmark and one of the largest in Europe.
Split into simpler sentences: The Grand Mosque of Copenhagen, officialyl known as the Hamad Bin Khalifa Civilisation Center, is a 21st-century Mosque in Copenhagen, Denmark. Built in 2014, it is the first purposely-built, non-Ahmadiyya Mosque, in Denmark and one of the largest in Europe.