This Rent Roll, dated 15 May 1628, names 153 leaseholders within the walled city of Londonderry
This database contains 3 fields: Surname, First Name and Lot Number belonging to leaseholder

The 'Muster rolls of foot companies in the garrison of Londonderry', dated May 1642-August 1643, names 905 men in 9 foot companies, consisting of 90 officers and 815 soldiers, who defended Derry's walls during the siege of 1641/42.

On 22 October 1641 the native Irish, under Sir Phelim O'Neill, rose in rebellion in Counties Londonderry and Tyrone, and the walled city of Londonderry became a refuge for Protestant settlers. A "League of the Captains of Londonderry" was set up to guard the city, with the raising of nine companies of foot soldiers, each assigned with a particular section of the walls of Derry to repair and to defend.

By April 1642 the city was close to starvation, with the rebel forces led by Sir Phelim O'Neill camped at Strabane. However, the threatened siege of Derry was lifted on 17 May 1642 by the defeat of the Irish army, led by the O'Cahans (O'Kanes), near Dungiven by an army consisting of east Donegal settlers and four Companies of soldiers from Londonderry.

This database consists of 4 fields: Surname, First Name, Rank and Foot Company.

'Defenders of Londonderry' refers to all those people (1,660 in total) who were named in contemporary sources and accounts as playing an active or supportive role in the successful Williamite campaign of 1689 to 1691 and were named in William R. Young's Fighters of Derry Their Deeds and Descendants: Being a Chronicle of Events in Ireland during the Revolutionary Period 1688-1691 (published by Eyre and Spottiswoode, London, 1932).

Many of the 'Defenders' fought at the Siege of Derry, which commenced with the closing of its gates on 7 December 1688 and ended on 31 July 1689 with the Jacobite army in retreat after a relief fleet, with essential food supplies, managed to break through the boom of fir and iron cable across the River Foyle.

The database of 'Defenders' consists of 5 fields: Young's ID, Surname, First Name, Residence; and Remarks. Young's ID refers to the identity number used by William Young for the 'defender' in his book. With this number researchers can consult Young's book to verify or gain additional information about any 'defender' recorded in the database. Biographical detail, where provided by Young, about a 'defender' and their planter origins in England, Scotland or Wales is inserted in the Remarks column.

A resolution, signed by 226 citizens of Londonderry, expressing condemnation of the plot to assassinate King William, was copied into the minute book of Londonderry Corporation on 16 April 1696. This is, in effect, a census of the walled city of Londonderry at the end of the 'Plantation' period. It is very noticeable that baptism, marriage and burial entries relating to many of these people are recorded in the registers of St. Columb's Cathedral, which commence in 1642.

There was a considerable surge in support for William III, who reigned as King of England, Scotland and Ireland from 1689 until his death on 8 March 1702, following the exposure of a Jacobite plan to assassinate him in 1696.

This database contains 3 fields: Surname, First Name and Remarks

Archibald Stewart's Survey of 1738 names 110 leaseholders within walled city of Londonderry

This database contains 3 fields: Surname, First Name and Lot Number belonging to leaseholder

Religious Census of 1766 - Returns survive for 10 civil parishes in County Derry

The Transportation Register identifies those people, male and female, who were tried and sentenced to transportation to Australia and were held 'in the Gaol of the County of Londonderry' in the time period 1839 to 1856 inclusive. In other words these men and women were convicted of committing crimes in County Derry and were held, prior to transportation, in the county jail on Bishop Street in Derry city. This jail closed in 1953 and was demolished in 1971, except for one turret of the jail which still stands today.

This database contains 7 fields: Surname, First Name, Age, Year Tried, Crime, Length of Transportation Sentence (in Years) and identification of cases where Sentence was commuted

Derry Almanac and Directory of 1921 name 8,000 heads of household in Derry city. From 1868 right through to 1949 inclusive each annual edition of the Derry Almanac and Directory contained a 'Street Directory' where heads of households were identified against their street address in Derry city. The recording of house numbers, against each householder, first appeared in the Almanac of 1897.

As the 1926 census for Northern Ireland was used for waste paper in World War II the first census that survives for city and county of Londonderry, since 1911, is for 1937 and this will be available for inspection in the year 2038 (unless the 100 year closure rule is waived before then). This means that each annual edition of Derry Almanac is the closest surviving census document for Derry city in the period from 1912 to 1936.

This database contains 5 fields: Surname, First Name, Street, House Number and Page Number