See also the History pages of the French Senate (in French).
In 1814, when the Bourbons returned to France, they drafted a new constitution or Charter, promulgated in June 1814, which established two legislative Houses on the English model. The upper house was a House of Peers (Chambre des Pairs) appointed by the king without limit on their numbers; their peerages were for life or hereditary, at his choosing. Male members of the royal family and descendants in male line of previous kings (princes du sang) were members by birth (pairs-nés), but needed explicit permission from the king to take their seat at each session.
A list of 154 peers was drawn on June 4, 1814. The peers' precedence was determined by their rank on that list. The list begins with the three surviving ecclesiastical peers (former archbishop of Reims, bishops of Langres and Châlons), followed by all surviving lay peers of the Old Regime peerage (with the exception of Aubigny, held by a British subject the duke of Richmond; but the duc de Valentinois, a.k.a. prince of Monaco, was made a peer); then came the prince of Benevento (Talleyrand), then all surviving hereditary dukes, a handful of brevet or courtesy dukes and princes of the Old Regime (prince de Poix, duc de Doudeauville, prince de Chalais, duc de Serent) and a duke of the old Comtat-Venassin, part of the Papal states until 1791 (Crillon). Then came Lebrun (duc de Plaisance) and nine of Napoleon's marshals (Berthier, Macdonald, Ney, Suchet, Gouvion-Saint-Cyr, Marmont, Oudinot, Moncey and Mortier). The rest of the list was made up of a mixture of royalists and most of the members of Napoleon's Senate (who had obligingly deposed their Emperor on April 3), and a few more marshals but alphabetically under their name or title (Cadore, Danzig, Pérignon, Serrurier, Valmy, Feltre).
Napoleon returned from Elba in March 1815 and issued a new constitution,
which featured a House of Peers, whose members were all hereditary. After
Napoleon's return and final defeat in 1815, Louis XVIII removed from the
peerage 29 individuals who had sided with Napoleon on July 24, 1815 (almost
all were reappointed in 1819). On Aug 17, 1815 94 peers were added.
On Aug. 19, 1815, the House of Peers was reformed and given its
final shape. The peerage was made hereditary for all members of the House
(except ecclesiastical members, of course), in male line and by primogeniture.
The king reserved the right to transfer the title to a collateral branch
of the original grantee in case of extinction of his direct line (the title
thus transferred retained its seniority). Each peer was to hold a title:
duke, marquis, count, viscount or baron. Existing peers were assigned ranks
and precedence within each rank by an ordonnance of Aug 31, 1817. These
titles did not necessarily supersede pre-existing titles (from the Old
Regime or Napoleon's Empire). Thus, a distinction needed to be made between
a vicomte and a vicomte-pair, and a baron-pair could be at the same time
a duc; and, while all members of the House of Peers were titled (as peers),
there were also titled members of the House of Deputies who were not peers.
Indeed, Louis XVIII and Charles X created many more hereditary titles with
majorats, but which were not peerages.
This is made all the more confusing since the Almanach Royal and other
official documents such as ordonnances appointing new peers often use the
old or even courtesy titles of the individuals, rather than their ranks
as peers. Only the letters patent delivered after formation of the majorat
specified on which bench (that is, with which rank) the new member joined
the House of Peers.
The procedural details were set forth in two Ordonnances of August 25, 1817. Louis XVIII decided to use a Napoleonic invention, the majorat (explained in the page on Napoleonic titles), and required all peers to form a majorat before entering the House. In many instances, a waiver was given and the newly appointed peer allowed to take his seat without a majorat; in that case, however, his title was not hereditary until the majorat had been formed; in effect, it was a life peerage. Majorats for dukes necessitated 30,000F of income, those for marquis and counts 20,000F, and for viscounts and barons 10,000F. As with Napoleon's majorats, the estates were landed, but government bonds (rentes) were also allowed. Majorats already formed under Napoleon were usually admitted.
Courtesy titles were provided for in law: the eldest son of a duc-pair had the title of marquis and his other sons that of comte, the eldest son of a marquis-pair had the title of comte and his other sons that of vicomte, etc. down to the eldest son of a baron-pair titled chevalier. Those titles, like their British courtesy equivalents, did not entitle to a seat in the House of Peers. The minimum age to enter the House was 25, and 30 to vote. The House of Peers was presided by the Chancelor of France. The precedence among peers was: princes of the blood, spiritual peers, temporal peers by title and within title by date of creation. An ordonnance of Jan 8, 1823 gave cardinals the rank of dukes, and bishops and archbishops the rank of counts.
On August 8, 1830 an Ordonnance of Louis-Philippe voided all the creations of peerages made by Charles X since his accession in September 1824. Then, on December 29, 1831 the Charte was amended. The peerages ceased to be hereditary, and all new creation were life peers. Moreover, the king's choice of new peers was restricted by law, by requiring him to choose them among certain categories: generals, former deputies, ambassadors, judges, etc (the restriction made little difference in practice, since peers were drawn from those categories anyway).
The House of Peers was abolished in February 1848 with the fall of the July Monarchy and never recreated. The last French peer, Gaston d'Orléans, comte d'Eu, died in 1922. Subsequent regimes after 1852 have all had an upper house (except the 4th Republic from 1946 to 1958), but only Napoleon III's Senate had lifetime appointments.
Restoration peers (1814-48) also used a mantle, but the outside was simply azure fringed with gold and lined with ermine. They used either a coronet or a Napoleonic toque or bonnet azure, circled ermine and surmounted with an plume or (art. 3 or the Ordonnance of Aug. 25, 1817 appears to leave them the choice).