The bulk of Milton’s poetry was written during 2 periods separated from each other by 20 years:
a) The period of his university career and his stay at Horton in his father’s house approximately between 1629 and 1640
b) The last years of his life from about 1660 and the year of his death 1674. The years in between were filled by a few sonnets.
Paradise lost was begun as early as 1658 and was first published nine years later in 1667. At first it was divided into ten books, but in the second edition it was reorganised in 12 books.
Before writing Paradise lost, Milton had had thoughts of writing a great national epic drawn from the legends of King Arthur and the Knights of the Round Table. After the Civil War he thought that a poem dealing with a Biblical subject would be more suitable for the struggles concerning the issues of conscience which he had witnessed and participated in.The poem is written in blank verse or unrhymed iambic pentameters: this verse form was first used by the Earl of Surrey in the 16th century in his translation of the Aeneid (about 1540). Blank verse has become one of the most widely used verse forms and has often been favoured by dramatists especially because its rhythm is very similar to everyday speech. It was the standard measure used by Tudor and Jacobean dramatists (like Shakespeare) and it was later used for reflective and narrative poems. Milton use of blank verse established a tradition in English poetry and was often imitated and also modified.