Complex sentence: In the 1960s and early 1970s, there was a renaissance in arts funding; government investment in the Arts Council of Great Britain's "Housing the Arts" fund enabled towns and cities all over the country either to renovate existing theatres, or commission new ones.
Split into simpler sentences: In the 1960s and early 1970s the British government invested in the Arts Council of Great Britain's "Housing the Arts" fund. The fund enabled towns and cities to renovate existing theatres, or commission new ones.