The surname Boase (Boas or Boaze) is thought to have originated in the very west of Cornwall in the parish of Paul just west of Penzance.  The earliest reference I have to the name is in the late1500’s in that parish. So far it has proved difficult to find any earlier references there; in large part because the parish records pre 1595 were destroyed when the Spanish landed at Mousehole and sacked the church at Paul.

On 23rd. July appearing to fulfil an old Cornish prophecy that strangers would 'burn Paul, Penzance and Newlyn'. 200 Spaniards land at Mousehole from 4 galleys. The Spaniard's set fire to Paul church and killed James Keigwin, John Pearce Peyton, James of Newlyn and Teck Cornall who were endeavouring to organise a defence. On being informed of the presence of the Spanish Sir Francis Godolphin gathered a makeshift force and hurried to Mousehole. On arriving they found that the Spanish had re-embarked and had sailed to Newlyn were the full force of 400 landed and fired Newlyn and Penzance. Sir Francis was powerless to intervene and the Spanish eventually fled after sighting the men-of-war sent from Plymouth by Drake to deal with them.

The very earliest references to the surname Boas come from Parish registers in Illogan. There appear to have been at least one man using the name as I have found a baptism for Jennet daughter of Pawle Boas in 1547, and a John in 1560, also son of Pawle.  There are a handful of other births in the mid to late 1500’s which I cannot place with any certainty but before long they appear to have moved to the parish of Paul.
In Paul there is the burial of a baby, Joan daughter of Edward and Agnes in 1601, which gives an approximate birth for Edward as 1570 so he could also be the son of Pawle.  There are also several marriages between 1600 and 1610 all in St Just.
From 1600 onwards the situation becomes a little clearer with a family living in Paul parish. There are certainly at this time 2 brothers – William and John who appear to have each married more than once and each had several children. These brothers I can be reasonably sure are the foundation for most if not all of the Boase families worldwide today.