1638 Prince Louis-Dieudonné of France, later King Louis XIV (1643-1715).
On his deathbed, Louis XIV, traditionally regarded as one of the greatest kings of France (r., 1643-1715), told his 5-year old great-grandson, who was about to become Louis XV, "I have been too fond of war; do not imitate me in that . . . ." It was plain statement of the truth; from the time Louis XIV assumed full power, at the age of 18 in 1661, France was at war for about 30 of the 54 years until his death
Oddly, the longest, most terrible, and most costly of these conflicts, the War of the Spanish Succession (1701-1714), might easily have been avoided.
The causus belli of the war was the death of the last Spanish Hapsburg, King Charles II (r. 1661-1700). Despite having been married twice, Charles died without leaving any children, probably due to impotence, and without any clear close relative eligible to succeed him. Now since Charles' health had always been precarious, the Spanish succession naturally interested the principal monarchs of Europe, Louis XIV, head of the House of Bourbon, and the Holy Roman Emperor Leopold I, head of the House of Hapsburg. Leopold had married Charles' sister, Margarita Teresa, while Louis had wed the Spanish king's half-sister, Maria Teresa, and thus both had heirs would could claim a tie to the Spanish throne.
Attempting to settle the matter peacefully, in 1668 Louis and Leopold agreed that upon the death of King Charles, the Spanish Empire would be divided. Louis would gain The Spanish Netherlands [Belgium], Lombardy, Sardinia, and Navarre, as well as Naples and Sicily (which France had been trying to conquer since the 13th century), plus the Philippines, while the Habsburg claimant to the throne would get Spain proper and the Americas. This seemed an equitable solution to the problem, since each dynasty gained something from the deal, while Spain was united with neither, which would have created an unprecedented superpower.
Alas for peaceful settle of international problems, when Charles finally died in 1700, Louis promptly decided to scrap the agreement, hoping to secure the entire Spanish Empire for his middle grandson, Philip of Anjou, then about 17. Naturally, Leopold, and most of the rest of Europe's monarchs objected.
The result was war, as the champions of the various claimants --at one point there were actually three!-- fought it out across much of Europe and goodly portions of the rest of the world as well. In the end, exhaustion, the deaths of some of the claimants, and Bourbon victories in Spain, led to the accession of Philip of Anjou as King Philip V of Spain, who would reign, with a slight interruption, until 1746, over a rather diminished Spanish Empire.
So Louis had gained the throne of France for his family -- though with tough treaty arrangements barring the merger of the two kingdoms under a single ruler. Of course Spain was devastated by the decade of war, while France’s economy was in a shambles. Worse, France had lost its colonies in Hudson’s Bay, Newfoundland, and Acadia to Britain, while Spain had lost the Spanish Netherlands, Naples, Lombardy, and Sardinia to Austria, Sicily to Piedmont, Minorca, in the Mediterranean and Gibraltar to Britain, and territories in South America to Portugal