The police system which, under the king, maintained the peace was partly organised on the basis of land tenure. As in the Sudan to-day the Omdah is held responsible for the robberies committed in his district, and as in China the head of a family may legally be called upon to answer for the transgressions of his kinsfolk, so King Alfred looked to the thane[7] to produce the culprit or satisfy the claim. The plan adopted counted on the assistance of self-interest for its complete success; the thane being a landed proprietor and consequently unable to dispose of his property secretly, was security to the king for all the members of his household--if any of them broke the law, his over-lord the thane was careful to bring him to justice. Yet poverty brought no exemption to the landless freeman. He too had to find a guarantee for his good behaviour; if he was unable to attach himself to some thane, he was compelled to combine with others in the same position as himself, in order that their joint goods or aggregate credit should provide sufficient bail for the shortcomings of any member of the society: the penalty incurred by those who could not, or would not, thus find the required security was that they were forbidden to possess cattle, and were no longer under the protection of the law. Freemen, therefore, who had no freehold, banded themselves together into "tythings": a tything consisted of the inhabitants of ten homesteads, and the members elected one of their number to be their "headborough,"[8] who thus became their representative, and was responsible for the community. The police organisation which we are considering is generally spoken of as the "Frankpledge system," frankpledge signifying the guarantee for peace maintenance demanded by the king from all free Englishmen, the essential properties of this responsibility being, that it should be local, and that it should be mutual. As we trace the history of police in England we shall see that these two qualities have survived through the successive stages of its evolution, and seem to be inseparable from our national conception of police functions.