Though the known history of the rock goes back to the Greeks and Phoenicians, no, before that to the neandertals, there is no local money before the British occupation.  At the start of the 19th century a series of copper merchant's tokens began which lasted about 20 years.  These came in quart and 2 quart denominations.  The commonest by far are the Robert Keeling 2 quarts of 1810.  They usually come in banged up VG-F.
     The tokens were succeeded in 1842 by regal coins denominated ½, 1, and 2 quarts.  I find these rather scarce.
     No coins were struck for Gibraltar for 125 years.  Then in 1967 the "crown" series began.  These are common in Unc, but I don't think they circulated.  I've never seen one with wear.  The 1967 silver proof version is not common compared with others of that ilk, such as the 1973 St. Helena crown, or Isle of Man material.
     Decimal coins got off to a slow start in 1971 with the popular Barbary Ape crown, followed the next year with the silver anniversary coin.  Both are pretty easy to find in either copper-nickel or silver.  Crowns in both metals have continued to be issued to this day.  Gold was introduced in 1975.  In 1988 a full British denomination set was released.
     I think it's fair to say at this point that the people who handle Gibraltar's coin program have adopted an "Isle-of-Man" type of strategy.  Since 1988 there have been numerous issues of all kinds of denominations, multiple types of a given denomination in a given year, and off metal strikes in silver, gold, and platinum.  On the whole these are harder to come by than the IOM stuff.  By and large the basic coins are obtainable, but I've never sought out the gold and platinum OMS pieces, so I can't compare them with anything.
     Finally we have the gold and silver ecu coins, meant to be the circulating precious metal ecu denominations, theoretically spendable anywhere in the EC.  I don't know about that.  The silver 10 pound is supposedly worth $18.00 face, more or less, which is not a bad markup for a coin with $1.00 and something worth of silver in it.  The gold 50 pound is similarly overvalued, though not by quite as large a margin.  Like the Djibouti 1500 francs coin I discussed elsewhere, their high face value has dampened their marketability, and I can't imagine anyone would go and spend them, so I'm fairly confident they won't be found in the future in circulated condition.  Why carry gold around when you can carry paper? (1994)