Short answers, pulled from the story.
The English Civil War began on the 22nd of August 1642 when King Charles I raised his standard at Nottingham. The conflict was triggered on the 4th of January 1642 when King Charles I entered the House of Commons with four hundred soldiers to arrest five members of Parliament.
The New Model Army was formed in 1645 under the Self-denying Ordinance with Thomas Fairfax as commander and Oliver Cromwell as Lieutenant-General of Horse. This professional fighting force replaced fragmented forces and proved decisive in battles such as Naseby on the 14th of June 1645.
King Charles I was executed on the 30th of January 1649 after being tried by a High Court of Justice set up in the name of the people of England. The court consisted of 59 Commissioners who judged Charles guilty of high treason and sentenced him to death.
The war was caused by King Charles I's belief in the Divine Right of Kings and his refusal to make concessions on taxation and religion. His reliance on extra-parliamentary income sources like ship money and his marriage to Henrietta Maria alarmed Protestant Englishmen and created deep resentment among the populace.
The English Civil War ended with the Restoration of the monarchy on the 29th of May 1660 when Charles II returned from exile. General George Monck organized the Convention Parliament which declared Charles II the lawful monarch and met for the first time on the 25th of April 1660.