These pewter mugs are the classic tankard style with glass bottoms often given as gifts to celebrate life's milestones.
There are many theories as to why these mugs have glass bottoms from the ability to judge the clarity and colour of the beer, to being able refuse the King's schilling and therefore conscription, or allowing the drinker to see if a fist is coming their way. Either way, these mugs have a long history in times of celebration.
In very good condition with only some minor dings. Take them to a jeweller and have your monogram or significant date engraved on them