Ialomița County has a total area of 4,453 km2 (1,719 sq mi). The county is situated in the Bărăgan Plain. The area is flat crossed by small rivers with small but deep valleys.
Its eastern border is on the Danube. The Ialomița River crosses the county from West to East about the middle. The Danube is split around the Ialomița Pond into the Old Danube branch and the Borcea branch.
Until 1940 (in the western part) and 1967 (in the eastern part) the county/plain was home of the great bustard (dropie in Romanian), with large populations of this bird. The birds disappeared because of the massive village buildout and hunting them for food.
Historically, the county was located in the southeastern part of Greater Romania, in the southeastern part of the historical region of Muntenia. The county comprised a large part of the current Ialomița County and of today's Călărași County. It was bordered to the west by Ilfov County, to the north by the counties of Prahova, Buzău and Brăila, to the east by Constanța County, and in the south by Durostor County.
With an area of 7,095 square kilometres (2,739 sq mi), Ialomița County was one of the largest counties of Greater Romania.
Administration
The county was originally divided administratively into five districts (plăși):[6]
According to the 1930 census data, the county population was 293,352 inhabitants, ethnically divided as follows: 96.6% Romanians, 2.5% Romanies, 0.2% Jews, as well as other minorities. From the religious point of view, the population was 99.3% Eastern Orthodox, 0.2% Jewish, 0.1% Roman Catholic, as well as other minorities.
Urban population
In 1930, the county's urban population was 34,260 inhabitants, comprising 90.2% Romanians, 6.0% Romnanies, 1.3% Jews, as well as other minorities. From the religious point of view, the urban population was composed of 97.4% Eastern Orthodox, 1.4% Jewish, 0.5% Roman Catholic, as well as other minorities.