Nobility of the First French Empire

As Emperor of the French, Napoleon I created titles of nobility to institute a stable elite in the First French Empire, after the instability resulting from the French Revolution.
Like many others, both before and since, Napoleon found that the ability to confer titles was also a useful tool of patronage which cost the state little treasure. In all, about 2,200 titles were created by Napoleon:
Napoleon also established a new knightly order in 1802, the Légion d'honneur, which is still in existence today. The Grand Dignitaries of the French Empire ranked, regardless of noble title, immediately behind the Princes of France.
Creation.
Ennoblement started in 1804 with the creation of princely titles for members of Napoleon's family, the House of Bonaparte. Other titles followed: in 1806, ducal titles were created and, in 1808, those of count, baron and knight.
Napoleon founded the concept of "nobility of Empire" by an imperial decree on 1 March 1808. The purpose of this creation was to amalgamate the old nobility and the revolutionary middle-class in one peerage system. This step, which aimed at the introduction of a stable elite, was fully in line with the creation of the Legion of Honour and of life senatorial peerages.
A council of the seals and the titles was also created and charged with establishing armorial bearings, and had a monopoly of this new nobility.
These creations are to be distinguished from an order such as the Order of the Bath. These titles of nobility did not have any true privileges, with two exceptions:
Hierarchy.
In Napoleon's nobility, there existed a strict and precise hierarchy of the titles, which granted office to some according to their membership of the imperial family, their rank in the army, or their administrative career in the civil or clerical administrations:
One could receive a title without exercising one of its enumerated functions. The title of marquis was not used during the First French Empire, and it therefore became very fashionable after the Bourbon Restoration, since it was not perceived to be tainted by the Napoleonic creations.
This nobility is essentially a "nobility of service", to a large extent made up of soldiers (67.9%), some civil servants (22%) and some collaborating members of the Ancien Régime. Napoleon's nobility was not abolished after the Bourbon Restoration, but it largely disappeared gradually for natural reasons, due in part to the great number of soldiers who had been promoted and subsequently died during the Napoleonic Wars.
In 1975, there were 239 remaining families belonging to the First Empire's nobility. Of those, perhaps about 135 were titled. Only one princely title (Essling, since Sievers is no longer used and Pontecorvo is merged with Prince Murat) and seven ducal titles remain today.
Heraldry.
Along with a new system of titles of nobility, the First French Empire also introduced a new system of heraldry.
Napoleonic heraldry was based on traditional heraldry but was characterised by a stronger sense of hierarchy. It employed a rigid system of additional marks in the shield to indicate official functions and positions. Another notable difference from traditional heraldry was the toques, which replaced coronets. The toques were surmounted by ostrich feathers: dukes had 7, counts had 5, barons had 3, and knights had 1. The number of lambrequins was also regulated: 3, 2, 1 and none respectively. As many grantees were self-made men, and the arms often alluded to their life or specific actions, many new or unusual charges were also introduced.
The most characteristic mark of Napoleonic heraldry was the additional marks in the shield to indicate official functions and positions. These came in the form of quarters in various colours, and would be differenced further by marks of the specific rank or function. In this system, the arms of knights had an ordinary gules, charged with the emblem of the Legion of Honour; Barons a quarter gules in chief sinister, charged with marks of the specific rank or function; counts a quarter azure in chief dexter, charged with marks of the specific rank or function; and dukes had a chief gules "semé" of stars argent.
The said 'marks of the specific rank or function' as used by Barons and Counts depended on the rank or function held by the individual. Military barons and counts had a sword on their quarter, members of the Conseil d'Etat had a chequy, ministers had a lion's head, prefects had a wall beneath an oak branch, mayors had a wall, landowners had a wheat stalk, judges had a balance, members of Academies had a palm, etc.
A decree of 3 March 1810 states: "The name, arms and livery shall pass from the father to all sons" although the distinctive marks of title could only pass to the son who inherited it. This provision applied only to the bearers of Napoleonic titles.
The Napoleonic system of heraldry did not outlast the First French Empire. The Second French Empire (1852–1870) made no effort to revive it, although the official arms of France were again those of Napoleon I.
Titles.
Princes.
There were three types of princely titles: 
Dukes.
There were three types of ducal titles: 
For a ducal title to be hereditary, it was necessary for the holder to have at least a 200,000 francs annual income and that the land which generated the income be held in a majorat for the inheritor of the dukedom.
These titles were allotted only to Marshals of the Empire and to certain ministers.
Counts.
The ordinary title of count ("comte") always went in front of the name. It was subject to the same rules as the title of duke but with an income threshold of only 30,000 francs.
Senators, Ministers, and Archbishops were all counts. From 1808 until 1814, 388 titles were created.
Barons.
The title of baron was comparable with that of count, except that the income threshold fell to 15,000 francs.
The mayors of the large cities and the bishops were all barons. Between 1808 and 1814, 1,090 titles of baron were created.
Today, the title of baron of the First French Empire is still claimed by families including d'Allemagne, Ameil, d'Andlau, d'Astorg, Auvray, Caffarelli, Christophe, Daru, Dein, Dubois, Eblé, Evain, Fabvier, de Croy, Fain, Géloes, Gourgaud, Guerrier de Dumast, Hamelin, Hottinguer, Laffitte, Lefebvre, Lepic, Méquet, Mallet, Marbot family, Martin de Lagarde, Massias, Nérin, Nicolas, Parmentier, Petiet, Pinoteau, Portalis, Rey, Rippert, Roederer, de Saint-Didier, de Saint-Geniès, de Saizieu, Salmon, de Saluce, Seillère, Strolz, Testot-Ferry, Thiry, de Villeneuve, Werlein.
Knights.
The title of knight ("chevalier") also went in front of the name. There was an obligation to have an income of at least 3,000 francs, and a majorat on the land generating the income was not obligatory.
All the knights of the Légion d’honneur received the title of "chevalier d'Empire" ("knight of the Empire"), but there had to be three generations of successive knights for the title to become hereditary. Between 1808 and 1814, 1,600 titles of knight were created.