Starting with Cromwell, a large percentage of the white labourer population were indentured servants and involuntarily transported people from Ireland. Irish servants in Barbados were often treated poorly, and Barbadian planters gained a reputation for cruelty.  The decreased appeal of an indenture on Barbados, combined with enormous demand for labour caused by sugar cultivation, led to the use of involuntary transportation to Barbados as a punishment for crimes, or for political prisoners, and also to the kidnapping of labourers who were sent to Barbados involuntarily. Irish indentured servants were a significant portion of the population throughout the period when white servants were used for plantation labour in Barbados, and while a "steady stream" of Irish servants entered the Barbados throughout the seventeenth century, Cromwellian efforts to pacify Ireland created a "veritable tidal wave" of Irish labourers who were sent to Barbados during the 1650s. Due to inadequate historical records, the total number of Irish labourers sent to Barbados is unknown, and estimates have been "highly contentious". While one historical source estimated that as many as 50,000 Irish people were transported to either Barbados or Virginia unwillingly during the 1650s, this estimate is "quite likely exaggerated". Another estimate that 12,000 Irish prisoners had arrived in Barbados by 1655 has been described as "probably exaggerated" by historian Richard B. Sheridan. According to historian Thomas Bartlett, it is "generally accepted" that approximately 10,000 Irish were sent to the West Indies involuntarily, and approximately 40,000 came as voluntary indentured servants, while many also travelled as voluntary, un-indentured emigrants.