Chronology and dating



As most genealogists know, dating conventions in English documents can cause problems even as late as the 18th century. These problems can become quite complicated in medieval documents. For example, medieval charters are commonly dated by specifying the week day, a nearby religious feast day, and the year of the monarch's reign - a convention which clearly has little in common with the modern system of day, month and calendar year.

Although the process of dating medieval documents can seem off-putting, fortunately most of the necessary resources are available on the internet. Today's genealogist can, with care, date a document at the push of a button, where yesterday's had to hunt laboriously through tables.

For further details, an excellent published guide is Cheney's Handbook of Dates for Students of English History, to which I am indebted for much of the following information.

The civil year versus the historical year

The first thing to be aware of is that, in England, from about the late 12th century until 1751 the civil, ecclesiastical and legal year began on 25 March, nearly three months later than the historical year. For dates in the intervening period, the historical year will therefore be different from the civil year. For example, the date we call 1 January 1751 (historical year) remains 1 January 1750 (civil year), because the civil year 1750 continues until 24 March. Clearly, for dates between 1 January and 24 March, the civil year is one less than the historical year. To avoid confusion, such dates are often written as 1 January 1750-1, or 1 January 1750/1.

Note that caution can be needed in dealing with very early records, as previously different conventions were used for the start of the year. In Anglo-Saxon and Norman times the year was generally reckoned from 25 December (i.e. three months before 25 March), and this usage lingered later in the Benedictine community. Earlier still, the year sometimes began in September.

The Julian and Gregorian calendars

In the same year that the start of the civil year was changed to 1 January, the 'new style' Gregorian calendar replaced the 'old style' Julian calendar in England (in September 1752, to be precise). The difference between the calendars concerns leap years - in the Julian calendar every fourth year is a leap year, whereas in the Gregorian calendar most centennial years are excepted from the rule. The main practical difficulty involved is that England made the change 170 years after most European countries. As a result, dates in England in the intervening period differ by more than a week from those in most of Continental Europe; obviously this is a problem only for people relating the dates of events in different countries. An online facility to Convert between Old and New Style dates is available - specifically, between the Julian calendar (with the year assumed to start on 25 March) and the Gregorian calendar (with the year starting 1 January).

Regnal years

The anno domini system of numbering years was introduced in England by Bede in the eighth century (and was presumably the most influential English invention of the Dark Ages!). However, from the late 12th century it became standard, instead, to date civil documents by the regnal year, that is, the year of the monarch's reign. (The use of anno domini persisted in ecclesiastical documents, and in some private charters.)

The date at which the regnal year began is unknown for the earliest kings, as documents were so rarely dated. From the time of Henry II to that of Henry III, it was considered to begin on the day of coronation, but from Edward II onwards it began on either the day of accession or the following day. With the help of a table of dates of accession (or coronation where appropriate), converting to anno domini is fairly straightforward. For example:

Henry VII succeeded to the throne at the Battle of Bosworth, 22 August 1485.
His first regnal year - usually written '1 Henry VII' - therefore covered 22 August 1485 to 21 August 1486.
Similarly, 8 Henry VII covered 22 August 1492 to 21 August 1493.
So an event dated - for example - 12 October 8 Henry VII would fall on 12 October 1492.

(Note that King John's regnal years are very awkward to deal with - he was crowned on Ascension Day, which falls on a different date each year. Perversely - to modern eyes - each of his regnal years therefore began on a different date. Worse still, as a result some of these 'years' are more than a year long, and therefore contain duplicate dates, which can present an insoluble problem.)

For a listing of medieval reigns, with hyperlinked calendars, click here.

Exchequer dating

To complicate regnal dating further, the medieval Exchequer used a different system of regnal years. The Exchequer year ran from Michaelmas to Michaelmas (30 September-29 September), and in most reigns it was assigned the number of the conventional regnal year in which it ended. For example, the first Exchequer year of Edward III, who succeeded to the throne on 25 January 1327, ran from 30 September 1326 to 29 September 1327 (and thus included the last few months of the reign of Edward II). In most Exchequer documents this would be referred to simply as the first year of Edward III.

Unfortunately, this rule was not followed consistently. In some reigns the Exchequer year was given the number of the conventional regnal year in which it began. For example, the first regnal year of Edward II, who succeeded on 8 July 1307, ran from 30 September 1307 to 29 September 1308. So it is necessary to consult a list of the dates of Exchequer years in different reigns. A reasonably convenient way of doing this is to perform a search of the National Archives catalogue, specifying the "Word or phrase" as the wildcard *, the "Department or Series code" as E 372 (for pipe rolls) and an appropriate range of years. The results will give show both the calendar years and the numbers of the Exchequer years.

Unfortunately even this is an over-simplification, because the Exchequer dated external events, and even some of its own records (the issue and receipt rolls), using conventional regnal years [Cheney, Handbook of Dates, p. 22]. It is not surprising that there has been so much confusion over Exchequer dating, even in published sources.

Religious festivals

From the thirteenth century, rather than specifying a day of the month, medieval documents were often dated relative to a nearby saint's day or other religious festival. For example:

(i) 'The day of the Translation of St Thomas the Martyr in the 46th year of Henry III'

The first stage in decoding dates like these is obviously to find the religious festival in question. Detailed biographical information about saints, including their feast days, can be found at Saints and Angels (Catholic Online). There is also a calendar of Saints Days compiled by Glenn Gunhouse (this is arranged chronologically, but can also be searched for particular saints).
Using these resources, and with the help of a table of regnal years, we find that:

The feast of the Translation of St Thomas the Martyr is on 7 July;
46 Henry III covers 28 October 1261 to 27 October 1262,
so the feast day is 7 July 1262.

(ii) 'Saturday after St Thomas the Apostle in in the 25th year of Edward I'

This example is obviously harder than the first. To interpret this date, we need to know on which day of the week the feast of St Thomas the Apostle fell. This can be found using the medieval English calendar section, by following the links until the calendar for the month in question is reached. In this way, the calculation proceeds as follows:

The feast of St Thomas the Apostle is on 21 December;
25 Edward I covers 20 November 1296 to 20 November 1297,
so the feast day is 21 December 1296.
The calendar for December 1296 shows that the 21st fell on a Friday,
So the Saturday after the feast day is 22 December 1296.

Moveable feasts

A further complication arises when the document is dated by reference to Easter or one of the associated feasts, which fall on a different date each year. The procedure is similar to that described above, except that the date of Easter in the relevant regnal year must first be found, instead of the saint's day.

The date of Easter Sunday is given, for each historical year and each regnal year, in the medieval English calendar section.

Roman-style dating

Another system sometimes used is the Roman one, of specifying days of the month as so many days before the following Kalends, Nones or Ides. The Kalends always fell on the 1st of the month; in March, May, July and October the Nones fell on the 7th and the Ides on the 15th; on other months they fell on the 5th and 13th respectively. In counting the number of days, the reference day itself was included. For example:

The Ides of March lie on 15 March;
the day before the Ides of March (pridie Idus) is 14 March;
the 3rd day before the Ides of March is 13 March (not 12 March!);
the 4th day before the Ides of March is 12 March, and so on.
The Kalends of June lie on 1 June;
the day before the Kalends of June is 31 May;
the 3rd day before the Kalends of June is 30 May and so on.

(Note that, in a leap year, the Romans gave February 29 days by inserting a duplicate 6th day before the Kalends of March. In this system, therefore, 25 February would be the 6th before the Kalends of March, and 24 February the second 6th before the Kalends.)

The Roman-style dates are given in the monthly calendars in the medieval English calendar section.

Undated documents

Finally, it should be noted that in early times documents were rarely dated at all. Thus, private charters are commonly dated only from the time of Edward I, and even royal charters are often undated in the 12th century and before. In these cases, dating becomes a matter of detective work, based on stylistic features and knowledge from other sources about the parties or witnesses. If the people involved are sufficiently eminent, this may not actually be very hard - comprehensive chronological lists of monarchs, officials, bishops and nobles are given in Fryde's Handbook of British Chronology. (For online lists of such office-holders, see below; for other useful resources, see the section on charters.)


Links and bibliography for chronology and dating

Contents:

General

Julian and Gregorian calendars

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Regnal years

On this web site:

Elsewhere on the internet:

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Religious festivals

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Weekdays

On this web site:

Elsewhere on the internet:

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Moveable feasts

On this web site:

Elsewhere on the internet:

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Chronological lists of office-holders

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Some published works on dating and chronology