Complex sentence: During Frederick IX's reign, Danish society shook off the restrictions of an agrarian society, developed a welfare state and, as a consequence of the booming economy of the 1960s, women entered the labour market.
Split into simpler sentences: During Frederick IX's reign, Danish society shook off the restrictions of an agrarian society and developed a welfare state. And, as a consequence of the booming economy of the 1960s, women entered the labour market.