Eostre Lore From Bede's The Reckoning of Time translated by Faith Wallis
Chapter 15: The English Months
In olden times the English people --for it did not seem fitting to me that I should speak of other nations' observance of the year and yet be silent about my own nation's-- calculated their months according to the course of the Moon. Hence, after the manner of the Greeks and the Romans, [the months] take their name from the Moon, for the moon is called mona and each month monath.
The first month, which the Latins call January, is Giuli; February is called Solmonath; March Hrethmonath; April, Eosturmonath[...]
Eosturmonath has a name which is now translated "Paschal month", and which was once called after a goddess of theirs named Eostre, in whose honour feasts were celebrated in that month. Now they designate that Paschal season by her name, calling the joys of the new rite by the time-honoured name of the old observance.