The area of the ancient county is 475,682 acres, with a population in 1891 of 185,284, and in 1901 of 195,764. The area of the administrative county is 479,358 acres. The county contains eight hundreds, of which three, namely Stoke, Burnham and Desborough, form the "Chiltern Hundreds" (q.v.). The hundred of Aylesbury retains its ancient designation of the "three hundreds of Aylesbury." The municipal boroughs are Buckingham, the county town (pop. 3152), and Wycombe, officially Chepping Wycombe, also Chipping or High Wycombe (15,542). The other urban districts are Aylesbury (9243), Beaconsfield (1570), Chesham (7245), Eton (3301), Fenny Stratford (4799), Linslade, on the Ouzel opposite to Leighton Buzzard in Bedfordshire (2157), Marlow (4526), Newport Pagnell (4028), Slough (11,453). Among the lesser market towns may be mentioned Amersham (2674), Ivinghoe (808), Olney (2684), Prince's Risborough (2189), Stony Stratford (2353), Wendover (2009) and Winslow (1703). At Wolverton (5323) are the carriage works of the London & North-Western railway.
Several of the villages on and near the banks of the Thames have become centres of residence, such as Taplow, Cookham and Bourne End, Burnham and Wooburn. Buckinghamshire is in the midland circuit, and assizes are held at Aylesbury. It has one court of quarter sessions, and is divided into thirteen petty sessional divisions. The boroughs of Buckingham and Wycombe have separate commissions of the peace. The administrative county contains 230 civil parishes. Buckinghamshire is almost entirely within the diocese of Oxford, and 215 ecclesiastical parishes are situated wholly or in part within it. There are three parliamentary divisions, Northern or Buckingham, Mid or Aylesbury, and Southern or Wycombe, each returning one member; and the county contains a small part of the parliamentary borough of Windsor (chiefly in Berkshire). The most notable institution within the county is Eton College, the famous public school founded by Henry VI.
The district which was to become Buckinghamshire was reached by the West Saxons in 571, as by a series of victories they pushed their way north along the Thames valley. With the grouping of the settlements into kingdoms and the consolidation of Mercia under Offa, Buckinghamshire was included in Mercia until, with the submission of that kingdom to the Northmen, it became part of the Danelaw. In the 10th century Buckinghamshire suffered frequently from the ravages of the Danes, and numerous barrows and earthworks mark the scenes of struggles against the invaders. These relics are especially abundant in the vale of Aylesbury, probably at this time one of the richest and best protected of the Saxon settlements. The Chiltern district, on the other hand, is said to have been an impassable forest infested by hordes of robbers and wild beasts. In the reign of Edward the Confessor, Leofstan, 12th abbot of St Albans, cut down large tracts of wood in this district and granted the manor of Hamstead (Herts) to a valiant knight and two fellow-soldiers on condition that they should check the depredations of the robbers.
The same reason led at an early period to the appointment of a steward of the Chiltern Hundreds, and this office being continued long after the necessity for it had ceased to exist, gradually became the sinecure it is to-day. The district was not finally disforested until the reign of James I.
At the time of the Norman invasion Buckinghamshire was probably included in the earldom of Leofwine, son of Godwin, and the support which it lent him at the battle of Hastings was punished by sweeping confiscations after the Conquest. The proximity of Buckinghamshire to London caused it to be involved in most of the great national events of the ensuing centuries. During the war between King John and his barons William Mauduit held Hanslape Castle against the king, until in 1216 it was captured and demolished by Falkes de Bréauté. The county was visited severely by the Black Death, and Winslow was one of many districts which were almost entirely depopulated. In the civil war Buckinghamshire was one of the first counties to join in an association for mutual defence on the side of the parliament, which had important garrisons at Aylesbury, Brill and elsewhere. Newport Pagnell was for a short time garrisoned by the royalist troops, and in 1644 the king fixed his headquarters at Buckingham.
The shire of Buckingham originated with the division of Mercia in the reign of Edward the Elder, and was probably formed by the aggregation of pre-existing hundreds round the county town, a fact which explains the curious irregularities of the boundary line. The eighteen hundreds of the Domesday survey have now been reduced to eight, of which the three Chiltern hundreds, Desborough, Burnham and Stoke, are unaltered in extent as well as in name. The remainder have been formed each by the union of three of the ancient hundreds, and Aylesbury is still designated "the three hundreds of Aylesbury." All, except Newport and Buckingham, retain the names of Domesday hundreds, and the shire has altered little on its outer lines since the survey. Until the time of Queen Elizabeth Buckinghamshire and Bedfordshire had a common sheriff. The shire court of the former county was held at Aylesbury.
The ecclesiastical history of Buckinghamshire is not easy to trace, as there is no local chronicler, but the earliest churches were probably subject to the West Saxon see of Dorchester, and when after the Conquest the bishop's stool was transferred to Lincoln no change of jurisdiction ensued. After the dissolution of the monasteries it was proposed to form a new diocese to include Bedfordshire and Buckinghamshire, but the project was abandoned, and both remained in the Lincoln diocese until 1837, when the latter was transferred to Oxford. The arch-deaconry was probably founded towards the close of the 11th century by Bishop Rémy, and the subdivision into rural deaneries followed shortly after. A dean of Thornborough is mentioned in the 12th century, and in the taxation of Nicholas IV. eight deaneries are given, comprising 186 parishes. In 1855 the deaneries were reconstructed and made eighteen in number.
On the redistribution of estates after the Conquest only two Englishmen continued to retain estates of any importance, and the chief landowners at this date were Walter Giffard, first earl of Buckingham, and Odo, bishop of Bayeux. Few of the great Buckinghamshire estates, however, remained with the same proprietors for any length of time. Many became annexed by religious establishments, while others reverted to the crown and were disposed of by various grants. The family of Hampden alone claim to have held the estate from which the name is derived in an unbroken line from Saxon times.
Buckinghamshire has always ranked as an agricultural rather than a manufacturing county, and has long been famed for its corn and cattle. Fuller mentions the vale of Aylesbury as producing the biggest bodied sheep in England, and "Buckinghamshire bread and beef" is an old proverb. Lace-making, first introduced into this county by the Fleming refugees from the Alva persecution, became a very profitable industry. The monopolies of James I. considerably injured this trade, and in 1623 a petition was addressed to the high sheriff of Buckinghamshire representing the distress of the people owing to the decay of bone lace-making. Newport Pagnell and Olney were especially famous for their lace, and the parish of Hanslape is said to have made an annual profit of £8000 to £9000 from lace manufacture. The straw-plait industry was introduced in the reign of George I., and formerly gave employment to a large number of the population.
The county was first represented in parliament by two members in 1290. The representation increased as the towns acquired representative rights, until in 1603 the county with its boroughs made a total return of fourteen members. By the Reform Act of 1832 this was reduced to eleven, and by the Redistribution of Seats Act of 1885 the boroughs were deprived of representation and the county returned three members for three divisions.