Charles O’Brien, 5th Viscount Clare, is mortally wounded in the Battle of Ramilles on May 23, 1706. He is the son of Daniel O’Brien, 3rd Viscount Clare and Philadelphia Lennard. He marries Charlotte Bulkeley, daughter of Henry Bulkeley and Sophia Stuart, on January 9, 1696, at Saint-Germain-en-Laye, France. Henry Bulkeley is the “Master of the Household” for Kings Charles II and James II. Charles O’Brien and Charlotte Bulkeley have two children, Charles O’Brien, 6th Viscount Clare (March 27, 1699 – September 9, 1761) and Henry O’Brien (born February 12, 1701).
The family fights as part of the Jacobite Irish Army during the War of the Two Kings, before going into exile in the Flight of the Wild Geese. Charles succeeds his brother, Daniel O’Brien, 4th Viscount Clare, to the title as 5th Viscount Clare in the Jacobite Peerage on his brother’s death from a mortal wound received in the Battle of Marsaglia in Italy on October 4, 1693. Charles is transferred from the Queen’s Dismounted Dragoons where he is a colonel, to the command of O’Brien’s Regiment on April 6, 1696. Later in the year he leads the regiment in the siege of Valenza in Lombardy, and the next year they are stationed with the army at Meuse.
By 1698 over one third of King James’ army is either dead or crippled, and when the Treaty of Ryswick ends the war between Louis and William, James’ soldiers are disbanded, unemployed, and homeless. Many become beggars but others join the Irish Brigade in the Spanish army, while others travel to Austria and enter the Catholic Corps.
Hostilities are renewed and Clare’s Regiment is assigned to the Army of Germany for two years in 1701-02. At the Battle of Cremona in 1702, the Irishmen defend the town against Prince Eugene and the imperial army. The attack is to be a surprise but the Wild Geese foil the attempt. The following year Lord Clare is promoted to brevet Brigadier of Infantry on April 2, 1703. A few months later on September 20, 1703, the unit takes part in the successful Battle of Hochstedt, better known as the Battle of Blenheim. A year later the unit is involved with the unsuccessful battle on August 13, 1704 at the second Battle of Blenheim. Although Clare’s Regiment experiences ups and downs, they are always admired. Two months after Blenheim, Charles rises to the brevet rank of Marshal-de-Camp on October 26, 1704, and a year later he is assigned to the Army of the Moselle under the Marshel de Villars. Clare’s Regiment fights in the disastrous Battle of Ramillies on May 23, 1706, where they distinguish themselves with great glory, but Lord Clare is mortally wounded and dies at Brussels, Belgium.
Due to the great service the O’Brien family has given to France, and having risked all, King Louis XIV makes sure that the regiment is kept in the family, and appoints Lt. Col. Murrough O’Brien (of the Carrigonnell O’Brien’s) as its commander until the minor Charles comes of age.