Squire

According to the Oxford Advanced Learner's Dictionary of Current English, a Squire was "a man of high social status who owned most of the land in a particular country area". Originally the word just means "attendant of a knight". Thus it had a great connotation with battlefield. But by Tudor times its terminology changed so that then "squire" or "esquire" referred to the lord of a manor.

In fact, the "esquire" is one of the four groups of the gentry. Members of that group had a lower status than the nobility but were socially far above the yeomen. In the 14th century the monarch could confer the honor of being a member of the gentry and by the 16th century the squire got certain offices like "Justice of the Peace".

Sources:

Oxford Advanced Learner's Dictionary of Current English

Oxford Companion to British History