Etymology

OE cāsere was inherited from an early Gmc borrowing of Lat Caeser, but a change of vocalism in ME indicates that it was replaced by another Gmc form. ON, cp. OIcel keiseri (cp. Go kaiser, suggesting PGmc *kaisar-), is the most likely source and provides the best explanation for the range of ME spellings attested, incl. <cayser> in Cl. The absence of final <-e> in some spellings could be taken as evidence instead of descent of some or all ME forms from OHG keisar, which does not show assimilation of the Lat ending -er to native agentive n. suffixes as in OE and ON, but it can equally well be explained as a native development (see Dance 2003: 426-8 for full discussion) and continuing influence from the Lat form is also likely.

PGmc Ancestor

*kaisar-

Proposed ON Etymon (OIcel representative)

keisari 'emperor'
(ONP keisari (sb.))

Other Scandinavian Reflexes

Far keisari, Icel keisari, Norw keisar, Dan kejser, Sw kejsare

OE Cognate

cāsere

Phonological and morphological markers

[ON /ei/ < PGmc */ai/] (may not be applicable)

Summary category

C2

Attestation

Cited by MED and OED with spellings indicating likely ON derivation from the Hatton Gospels (see DOE) and Orrm onwards.
 

Occurrences in the Gersum Corpus

Cl 1322, 1374, 1593; Erk 199

Bibliography

MED caiser (n.) , OED Caeser (n.1) , HTOED , Bj. 56-7, de Vries keiseri, Mag. keisari, DOE cāsere, AEW cāsere