Complex sentence: Parliaments were then for a seven-year term, and it was the custom not to go to the country until the sixth year unless forced to by events, and only four and a half years had passed since the last general election.
Split into simpler sentences: Parliaments were then for a seven-year term, and it was the custom not to go to the country until the sixth year unless forced to by events. Only four and a half years had passed since the last general election.