The original Big Bertha came along in 1991, at a time when most golfers were still using persimmon drivers. It clocked in at a whopping 190cc. That's only about 40-percent as large as today's drivers, and is the size of some of today's 3-woods. But back then, a 190cc driver head was huge.
a Mike Royko column explained, quoting a Callaway spokesperson:
"We explain it in our catalog. It is named after a famous cannon. It was made in Germany in 1917, by Baron von Krupp, of the Krupp munitions makers.
"The baron's daughter was named Bertha, and he called it Big Bertha after his daughter. We thought it was a cute name to describe the world's biggest driver."
Royko was having some fun with the idea that plump women named Bertha might be offended that such a humungous driver head was named after them. I'm more surprised that the name, at the time, didn't draw the ire of, well, somebody, because it was named after an armament built by WWI axis power (and our enemy then and later) Germany.
At the time, most driver clubheads were in the neighborhood of 145 cubic centimeters - smaller than some of today's hybrids. If you're not old enough to remember those drivers, well, just think about that for a while.
By 1992, other manufacturers were building their own "gigantic" drivers. Wilson made one called the Killer Whale that was a much-larger 275cc (still tiny by today's standards).
Those larger drivers - we remember them as "oversized" drivers now, but at the time they were just as likely to be called "wide body" drivers - were selling like hotcakes by 1992. But there was concern it was just a trend that might die out. From a 1992 New York Times article, there's this:
How big can oversize go? Frank Thomas, technical director for the United States Golf Association, in Far Hills, N.J., said the trend in metal wide-body drivers appeared to be self-limiting. If the club heads get much bigger than they are now, wind resistance could be a problem. Finding the right mix of metals is important, too. "You need a really rigid face on the club," he added. "Anything with flexibility will hurt you rather than help you."
Frank Thomas was right about a lot of things, and he was wrong about a lot of things. He was very wrong in those comments about the successors to the original Big Bertha.