In Domesday Book it is called Elerchi, which signifies the swan’s
house or swannery; for Elerk in Cornish is a swan, and there are the
remains of a large pool under the house, which seems to have been
designed to that end.
It is in the said book inserted among the manors given by William the
Conqueror, to his half-brother Robert Earl of Morton and Cornwall.
Francis Tregian, esq. among the rest of his estates, forfeited his
half of this manor.